tag:blogger.com,1999:blog-60922180649260859312024-03-12T17:34:43.339-07:00SOLAR SYSTEMUnknownnoreply@blogger.comBlogger14125tag:blogger.com,1999:blog-6092218064926085931.post-68029107035776972642011-03-16T18:26:00.000-07:002011-03-16T18:27:12.444-07:00SUN AND PLANET SUMMARY<div dir="ltr" style="text-align: left;" trbidi="on"><div class="separator" style="clear: both; text-align: center;"></div><div class="separator" style="clear: both; text-align: center;"></div><div class="separator" style="clear: both; text-align: center;"></div><div class="separator" style="clear: both; text-align: center;"></div><div class="separator" style="clear: both; text-align: center;"></div><div class="separator" style="clear: both; text-align: center;"><span style="font-family: "Arial", "Helvetica", sans-serif;">The following table lists statistical information for the Sun and planets:</span></div><div class="separator" style="clear: both; text-align: center;"></div><div class="separator" style="clear: both; text-align: center;"></div><div class="separator" style="clear: both; text-align: center;"></div><div class="separator" style="clear: both; text-align: center;"></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjYmfAT4OEBnFMD-7aj-8A9U1vpVxOQlJew-jyJdyrbAiC_NX6BHNjL96iptdoj_OK_V5DLjJxWQ6AwzXEMRb4ozLB8LHF45CKZ9C-uoYkxaFZ6hhWRn4k4eDcvAX3JnRI1yhrnsKHVUZm7/s1600/sun+and+planet+summary.bmp" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="235" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjYmfAT4OEBnFMD-7aj-8A9U1vpVxOQlJew-jyJdyrbAiC_NX6BHNjL96iptdoj_OK_V5DLjJxWQ6AwzXEMRb4ozLB8LHF45CKZ9C-uoYkxaFZ6hhWRn4k4eDcvAX3JnRI1yhrnsKHVUZm7/s400/sun+and+planet+summary.bmp" width="400" /></a></div>* The Sun's period of rotation at the surface varies from approximately 25 days at the equator to 36 days at the poles. Deep down, below the <a href="http://www.solarviews.com/eng/terms.htm#convection">convective</a> zone, everything appears to rotate with a period of 27 days.</div>Unknownnoreply@blogger.com1tag:blogger.com,1999:blog-6092218064926085931.post-27204157832951463522011-03-12T15:30:00.000-08:002011-03-15T13:22:04.493-07:00THE SOLAR SYSTEM<div dir="ltr" style="text-align: left;" trbidi="on"><div align="center"><span style="font-family: "Courier New", "Courier", monospace;"><b><span style="color: #444444;">For I dipped into the Future, far as human eye could see; saw the vision of the world, and all the wonder that would be. -Alfred Lord Tennyson, 1842</span></b></span></div><div align="left"><br />
</div><div align="left"><span style="font-family: "Georgia", "Times New Roman", serif;">Our solar system consists of an average star we call the <a href="http://oursolarsysteminfo.blogspot.com/2011/03/sun.html">Sun</a>, the planets <a href="http://oursolarsysteminfo.blogspot.com/2011/03/mercury.html">Mercury</a>, <a href="http://oursolarsysteminfo.blogspot.com/2011/03/venus.html">Venus</a>, <a href="http://oursolarsysteminfo.blogspot.com/2011/02/earth.html">Earth</a>, <a href="http://oursolarsysteminfo.blogspot.com/2011/02/mars.html">Mars</a>, <a href="http://oursolarsysteminfo.blogspot.com/2011/02/jupiter.html">Jupiter</a>, <a href="http://oursolarsysteminfo.blogspot.com/2011/02/saturn.html">Saturn</a>, <a href="http://oursolarsysteminfo.blogspot.com/2011/02/uranus-is-seventh-planet-from-sun-and.html">Uranus</a>, <a href="http://oursolarsysteminfo.blogspot.com/2011/02/neptune.html">Neptune</a>, and <a href="http://oursolarsysteminfo.blogspot.com/2011/02/pluto.html">Pluto</a>. It includes: the satellites of the planets; numerous <a href="http://www.solarviews.com/eng/comet.htm">comets</a>, <a href="http://www.solarviews.com/eng/asteroid.htm">asteroids</a>, and meteoroids; and the interplanetary medium. The Sun is the richest source of electromagnetic energy (mostly in the form of heat and light) in the solar system. The Sun's nearest known stellar neighbor is a red dwarf star called Proxima Centauri, at a distance of 4.3 <a href="http://www.solarviews.com/eng/terms.htm#lightyear">light years </a>away. The whole solar system, together with the local stars visible on a clear night, orbits the center of our home galaxy, a spiral disk of 200 billion stars we call the <a href="http://www.solarviews.com/eng/solarsys.htm#milky">Milky Way</a>. The Milky Way has two small galaxies orbiting it nearby, which are visible from the southern hemisphere. They are called the Large Magellanic Cloud and the Small Magellanic Cloud. The nearest large galaxy is the <a href="http://www.solarviews.com/eng/solarsys.htm#andromeda">Andromeda Galaxy</a>. It is a spiral galaxy like the Milky Way but is 4 times as massive and is 2 million light years away. Our galaxy, one of billions of galaxies known, is traveling through intergalactic space. <br />
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The planets, most of the satellites of the planets and the asteroids revolve around the Sun in the same direction, in nearly circular orbits. When looking down from above the Sun's north pole, the planets orbit in a counter-clockwise direction. The planets orbit the Sun in or near the same plane, called the <a href="http://www.solarviews.com/eng/terms.htm#ecliptic">ecliptic</a>. Pluto is a special case in that its orbit is the most highly inclined (18 degrees) and the most highly elliptical of all the planets. Because of this, for part of its orbit, Pluto is closer to the Sun than is Neptune. The axis of rotation for most of the planets is nearly perpendicular to the ecliptic. The exceptions are Uranus and Pluto, which are tipped on their sides.</span><span style="color: #444444;"><br />
</span><span style="font-family: "Courier New", "Courier", monospace;"><b><span style="color: #444444;"> </span></b></span></div><div align="left"><b><span style="font-family: "Georgia", "Times New Roman", serif;"><span style="color: #b45f06;">Composition Of The Solar System</span></span></b><span style="font-family: "Courier New", "Courier", monospace;"><b><span style="color: #444444;"> </span></b></span></div><div align="left"><br />
</div><div align="left"><span style="font-family: "Georgia", "Times New Roman", serif;">The Sun contains 99.85% of all the matter in the Solar System. The planets, which condensed out of the same disk of material that formed the Sun, contain only 0.135% of the mass of the solar system. Jupiter contains more than twice the matter of all the other planets combined. Satellites of the planets, comets, asteroids, meteoroids, and the interplanetary medium constitute the remaining 0.015%. The following table is a list of the mass distribution within our Solar System.</span><span style="font-family: "Courier New", "Courier", monospace;"><b><span style="color: #444444;"> </span></b></span></div><div align="left"><br />
</div><ul style="text-align: left;"><li align="left">Sun: 99.85%</li>
<li align="left"> Planets: 0.135%</li>
<li align="left"> Comets: 0.01% ?</li>
<li align="left"> Satellites: 0.00005%</li>
<li align="left"> <a href="http://www.solarviews.com/eng/terms.htm#minor">Minor Planets</a>: 0.0000002% ?</li>
<li align="left"> Meteoroids: 0.0000001% ?</li>
<li align="left">Interplanetary Medium: 0.0000001% ?</li>
</ul><div style="text-align: left;"><span style="font-family: "Georgia", "Times New Roman", serif;"><b><span style="color: #b45f06;">Interplanetary Space</span></b></span></div><div style="text-align: left;"><br />
</div><div style="text-align: left;"><span style="font-family: "Georgia", "Times New Roman", serif;">Nearly all the solar system by volume appears to be an empty void. Far from being nothingness, this vacuum of "space" comprises the interplanetary medium. It includes various forms of energy and at least two material components: interplanetary dust and interplanetary gas. Interplanetary dust consists of microscopic solid particles. Interplanetary gas is a tenuous flow of gas and charged particles, mostly protons and electrons -- <a href="http://www.solarviews.com/eng/terms.htm#plasma">plasma</a> -- which stream from the Sun, called the <a href="http://www.solarviews.com/eng/terms.htm#solarwind">solar wind</a>.</span></div><div style="text-align: left;"><br />
</div><div class="separator" style="clear: both; text-align: center;"></div><div class="separator" style="clear: both; text-align: center;"></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj3c-OjsJO-X9NsfLJ3o0olJP_rN05BwU7jZILxHcJWCeZmygvZ0RvfEMswLXcb2sRH-hS8M2Q0280yz1caGIbgtewhDaIF33A05gbTBbRmFX75lq76W9DHSnMRX1Zn4WfJoe3836r4Zaj-/s1600/solarwnd.gif" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="176" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj3c-OjsJO-X9NsfLJ3o0olJP_rN05BwU7jZILxHcJWCeZmygvZ0RvfEMswLXcb2sRH-hS8M2Q0280yz1caGIbgtewhDaIF33A05gbTBbRmFX75lq76W9DHSnMRX1Zn4WfJoe3836r4Zaj-/s320/solarwnd.gif" width="320" /></a></div><div style="text-align: left;"><span style="font-family: "Georgia", "Times New Roman", serif;"> The solar wind can be measured by spacecraft, and it has a large effect on comet tails. It also has a measurable effect on the motion of spacecraft. The speed of the solar wind is about 400 kilometers (250 miles) per second in the vicinity of Earth's orbit. The point at which the solar wind meets the interstellar medium, which is the "solar" wind from other stars, is called the heliopause. It is a boundary theorized to be roughly circular or teardrop-shaped, marking the edge of the Sun's influence perhaps 100 AU from the Sun. The space within the boundary of the heliopause, containing the Sun and solar system, is referred to as the heliosphere. <br />
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The solar magnetic field extends outward into interplanetary space; it can be measured on Earth and by spacecraft. The solar magnetic field is the dominating magnetic field throughout the interplanetary regions of the solar system, except in the immediate environment of planets which have their own magnetic fields.</span></div><div style="text-align: left;"><br />
</div><div style="text-align: left;"><b><span style="font-family: "Georgia", "Times New Roman", serif;"><span style="color: #b45f06;"> The Terrestrial Planets</span> </span></b></div><div style="text-align: left;"><br />
</div><div style="text-align: left;"><span style="font-family: "Georgia", "Times New Roman", serif;">The terrestrial planets are the four innermost planets in the solar system, Mercury, Venus, Earth and Mars. They are called terrestrial because they have a compact, rocky surface like the Earth's. The planets, Venus, Earth, and Mars have significant atmospheres while Mercury has almost none. The following diagram shows the approximate distance of the terrestrial planets to the Sun.</span></div><div style="text-align: left;"><br />
</div><div style="text-align: left;"><span style="font-family: "Georgia", "Times New Roman", serif;"><span style="color: #b45f06;"><b>The Jovian Planets</b></span> </span><b><span style="font-family: "Georgia", "Times New Roman", serif;"> </span></b></div><div style="text-align: left;"><br />
</div><div style="text-align: left;"><span style="font-family: "Georgia", "Times New Roman", serif;"> Jupiter, Saturn, Uranus, and Neptune are known as the Jovian (Jupiter-like) planets, because they are all gigantic compared with Earth, and they have a gaseous nature like Jupiter's. The Jovian planets are also referred to as the gas giants, although some or all of them might have small solid cores. The following diagram shows the approximate distance of the Jovian planets to the Sun.</span></div><div style="text-align: left;"><br />
</div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhnIQazDHwU-ZhPAUW5tSVlFv-w_kCNzEFZeS9v4jdrvokdcgxslojRcQv3s4t5aGzmuQNIk07qFrDSpqv1M27elfhqAYYCHvWMZZj0ly60SgVNThT9Gln66xtV5Fs93JxqR92DiHS6yaYz/s1600/inner.gif" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="304" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhnIQazDHwU-ZhPAUW5tSVlFv-w_kCNzEFZeS9v4jdrvokdcgxslojRcQv3s4t5aGzmuQNIk07qFrDSpqv1M27elfhqAYYCHvWMZZj0ly60SgVNThT9Gln66xtV5Fs93JxqR92DiHS6yaYz/s320/inner.gif" width="320" /></a></div><div style="text-align: left;"><br />
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</div><div style="text-align: left;"><span style="font-family: "Georgia", "Times New Roman", serif;"><b><span style="color: #b45f06;"></span></b></span></div><div style="text-align: left;"><span style="font-family: "Georgia", "Times New Roman", serif;"><b><span style="color: #b45f06;"></span></b></span></div><div style="text-align: left;"><span style="font-family: "Georgia", "Times New Roman", serif;"><b><span style="color: #b45f06;"></span></b></span></div><div style="text-align: left;"><span style="font-family: "Georgia", "Times New Roman", serif;"><b><span style="color: #b45f06;"></span></b></span></div><div style="text-align: left;"><span style="font-family: "Georgia", "Times New Roman", serif;"><b><span style="color: #b45f06;"></span></b></span></div><div style="text-align: left;"><span style="font-family: "Georgia", "Times New Roman", serif;"><b><span style="color: #b45f06;"><br />
</span></b></span></div></div>Unknownnoreply@blogger.com3tag:blogger.com,1999:blog-6092218064926085931.post-7878868752160351212011-03-10T09:30:00.000-08:002011-03-15T13:38:21.334-07:00SUN<div dir="ltr" style="text-align: left;" trbidi="on"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Our <a href="http://oursolarsysteminfo.blogspot.com/2011/03/sun.html">Sun</a> is a normal main-sequence <a href="http://nineplanets.org/help.html#obaf">G2</a> star, one of more than 100 <a href="http://nineplanets.org/help.html#billion">billion</a> stars in our galaxy.</span></b><br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEja1S76VxvQZhqLb39c0v0GIJUtnAq-81ui1G2sW1GghyphenhyphendLz7CzoEE_nCQQmFOGB5EWrdRf0sLwtrboVZMVHTqECDoYb_PMhmXHVNlaYokjgPCNvvXg46yLL82ysv_pHijwRAh75BNlEfqo/s1600/Our-Sun.jpg" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="160" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEja1S76VxvQZhqLb39c0v0GIJUtnAq-81ui1G2sW1GghyphenhyphendLz7CzoEE_nCQQmFOGB5EWrdRf0sLwtrboVZMVHTqECDoYb_PMhmXHVNlaYokjgPCNvvXg46yLL82ysv_pHijwRAh75BNlEfqo/s200/Our-Sun.jpg" width="200" /></a></div><br />
<b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> <a href="http://nineplanets.org/data1.html">diameter:</a> 1,390,000 <a href="http://nineplanets.org/help.html#km">km</a>.</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> <a href="http://www.blogger.com/">mass:</a> <a href="http://nineplanets.org/help.html#expnot">1.989e30</a> <a href="http://nineplanets.org/help.html#kg">kg</a></span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> <a href="http://nineplanets.org/data2.html">temperature:</a> 5800 <a href="http://nineplanets.org/help.html#kelvin">K</a> (surface)</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> 15,600,000 K (core)</span></b><br />
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<b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">The Sun is by far the <a href="http://nineplanets.org/datamax.html#largest">largest</a> object in the solar system. It contains more than 99.8% of the total mass of the Solar System (<a href="http://oursolarsysteminfo.blogspot.com/2011/02/jupiter.html">Jupiter</a> contains most of the rest).</span></b><br />
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<b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">It is often said that the Sun is an "ordinary" star. That's true in the sense that there are many others similar to it. But there are many more smaller stars than larger ones; the Sun is in the top 10% by mass. The median size of stars in our galaxy is probably less than half the mass of the Sun.</span></b><br />
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<b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">The Sun is personified in many mythologies: the Greeks called it <a href="http://www.pantheon.org/articles/h/helios.html">Helios</a> and the Romans called it <a href="http://www.pantheon.org/articles/s/sol_2.html">Sol</a>. </span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">The Sun is, at present, about 70% <a href="http://cst.lanl.gov/CST/imagemap/periodic/1.html">hydrogen</a> and 28% <a href="http://cst.lanl.gov/CST/imagemap/periodic/2.html">helium</a> by mass everything else ("<a href="http://nineplanets.org/help.html#metal">metals</a>") amounts to less than 2%. This changes slowly over time as the Sun converts hydrogen to helium in its core.</span></b><br />
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<b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">The outer layers of the Sun exhibit differential rotation: at the equator the surface rotates once every 25.4 days; near the poles it's as much as 36 days. This odd behavior is due to the fact that the Sun is not a solid body like the Earth. Similar effects are seen in the <a href="http://nineplanets.org/overview.html#gas_p">gas planets</a>. The differential rotation extends considerably down into the interior of the Sun but the core of the Sun rotates as a solid body. </span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Conditions at the Sun's core (approximately the inner 25% of its radius) are extreme. The temperature is 15.6 million Kelvin and the pressure is 250 billion <a href="http://nineplanets.org/help.html#atm">atmospheres</a>. At the center of the core the Sun's density is more than 150 times that of water. </span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">The Sun's power (about 386 billion billion megaWatts) is produced by <a href="http://nineplanets.org/help.html#fusion">nuclear fusion</a> reactions. Each second about 700,000,000 tons of hydrogen are converted to about 695,000,000 tons of helium and 5,000,000 tons (=3.86e33 ergs) of energy in the form of gamma rays. As it travels out toward the surface, the energy is continuously absorbed and re-emitted at lower and lower temperatures so that by the time it reaches the surface, it is primarily visible light. For the last 20% of the way to the surface the energy is carried more by <a href="http://nineplanets.org/help.html#convection">convection</a> than by radiation. </span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">The surface of the Sun, called the photosphere, is at a temperature of about 5800 K. Sunspots are "cool" regions, only 3800 K (they look dark only by comparison with the surrounding regions). Sunspots can be very large, as much as 50,000 km in diameter. Sunspots are caused by complicated and not very well understood interactions with the Sun's magnetic field. </span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">A small region known as the chromosphere lies above the photosphere.</span></b><br />
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<b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">The highly rarefied region above the chromosphere, called the corona, extends millions of kilometers into space but is visible only during a total solar eclipse (left). Temperatures in the corona are over 1,000,000 K.</span></b><br />
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<b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">It just happens that the Moon and the Sun appear the same size in the sky as viewed from the Earth. And since the Moon orbits the Earth in approximately the same plane as the Earth's orbit around the Sun sometimes the Moon comes directly between the Earth and the Sun. This is called a solar eclipse; if the alignment is slighly imperfect then the Moon covers only part of the Sun's disk and the event is called a partial eclipse. When it lines up perfectly the entire solar disk is blocked and it is called a total eclipse of the Sun. Partial eclipses are visible over a wide area of the Earth but the region from which a total eclipse is visible, called the path of totality, is very narrow, just a few kilometers (though it is usually thousands of kilometers long). Eclipses of the Sun happen once or twice a year. If you stay home, you're likely to see a partial eclipse several times per decade. But since the path of totality is so small it is very unlikely that it will cross you home. So people often travel half way around the world just to see a total solar eclipse. To stand in the shadow of the Moon is an awesome experience. For a few precious minutes it gets dark in the middle of the day. The stars come out. The animals and birds think it's time to sleep. And you can see the solar corona. It is well worth a major journey.</span></b><br />
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<b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">The Sun's magnetic field is very strong (by terrestrial standards) and very complicated. Its <a href="http://nineplanets.org/help.html#magnetosphere">magnetosphere</a> (also known as the <a href="http://nineplanets.org/medium.html#heliopause">heliosphere</a>) extends well beyond <a href="http://oursolarsysteminfo.blogspot.com/2011/02/pluto.html">Pluto</a>. </span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">In addition to heat and light, the Sun also emits a low density stream of charged particles (mostly electrons and protons) known as the solar wind which propagates throughout the solar system at about 450 km/sec. The solar wind and the much higher energy particles ejected by solar flares can have dramatic effects on the Earth ranging from power line surges to radio interference to the beautiful <a href="http://nineplanets.org/help.html#aurora">aurora</a> borealis. </span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Recent data from the spacecraft <a href="http://nineplanets.org/spacecraft.html#ulysses">Ulysses</a> show that during the minimum of the solar cycle the solar wind emanating from the polar regions flows at nearly double the rate, 750 kilometers per second, than it does at lower latitudes. The composition of the solar wind also appears to differ in the polar regions. During the solar maximum, however, the solar wind moves at an <a href="http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=24671">intermediate speed</a>. </span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Further study of the solar wind will be done by the recently launched <a href="http://nineplanets.org/spacecraft.html#wind">Wind</a>, <a href="http://www.srl.caltech.edu/ACE/">ACE</a> and <a href="http://sohowww.nascom.nasa.gov/">SOHO</a> spacecraft from the dynamically stable vantage point directly between the Earth and the Sun about 1.6 million km from Earth. </span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">The solar wind has large effects on the tails of comets and even has measurable effects on the trajectories of spacecraft. </span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Spectacular loops and prominences are often visible on the Sun's limb (left). </span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">The Sun's output is not entirely constant. Nor is the amount of sunspot activity. There was a period of very low sunspot activity in the latter half of the 17th century called the Maunder Minimum. It coincides with an abnormally cold period in northern Europe sometimes known as the Little Ice Age. Since the formation of the solar system the Sun's output has increased by about 40%.</span></b><br />
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<b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">The Sun is about 4.5 billion years old. Since its birth it has used up about half of the hydrogen in its core. It will continue to radiate "peacefully" for another 5 billion years or so (although its luminosity will approximately double in that time). But eventually it will run out of hydrogen fuel. It will then be forced into radical changes which, though commonplace by stellar standards, will result in the total destruction of the Earth (and probably the creation of a <a href="http://astro.nineplanets.org/twn/types.html#planetary">planetary nebula</a>). </span></b><br />
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<b><span style="font-family: "Georgia", "Times New Roman", serif;"><span style="font-size: large;"><span style="color: #6aa84f;">The Sun's satellites </span></span></span></b><br />
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<b><span style="font-size: small;"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">There are eight planets and a large number of <a href="http://nineplanets.org/smallbodies.html">smaller objects</a> orbiting the Sun. (Exactly which bodies should be classified as planets and which as "smaller objects" has been the source of some <a href="http://nineplanets.org/overview.html#classification">controversy</a>, but in the end it is really only a matter of definition. Pluto is no longer officially a planet but we'll keep it here for history's sake.)</span></span></b><b><span style="font-family: "Georgia", "Times New Roman", serif;"><span style="font-size: large;"><span style="color: #6aa84f;"> </span></span></span></b><br />
<b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> </span></b><br />
<b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> </span></b><br />
<b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><span style="font-family: "Georgia", "Times New Roman", serif;"><b>Distance Radius Mass</b></span><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><b><span style="font-family: "Georgia", "Times New Roman", serif;">Planet (000 km) (km) (kg) </span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
--------- ------------ ------ ------- </span></b><br />
<span style="font-family: inherit;"><a href="http://oursolarsysteminfo.blogspot.com/2011/03/mercury.html">MERCURY</a></span><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> </span></b><span style="font-family: inherit;"> 57,910 2439 3.30e23</span><br />
<span style="font-family: inherit;"><a href="http://oursolarsysteminfo.blogspot.com/2011/03/venus.html">Venus</a> 108,200 6052 4.87e24</span><br />
<span style="font-family: inherit;"><a href="http://oursolarsysteminfo.blogspot.com/2011/02/earth.html">Earth</a> 149,600 6378 5.98e24 </span><span style="font-family: inherit;"><br />
</span><span style="font-family: inherit;"><a href="http://oursolarsysteminfo.blogspot.com/2011/02/mars.html">Mars</a> 227,940 3397 6.42e23 </span><span style="font-family: inherit;"><br />
</span><span style="font-family: inherit;"><a href="http://oursolarsysteminfo.blogspot.com/2011/02/jupiter.html">Jupiter</a> 778,330 71492 1.90e27</span><span style="font-family: inherit;"><br />
</span><span style="font-family: inherit;"><a href="http://oursolarsysteminfo.blogspot.com/2011/02/saturn.html">Saturn</a> 1,426,940 60268 5.69e26 </span><span style="font-family: inherit;"><br />
</span><span style="font-family: inherit;"><a href="http://oursolarsysteminfo.blogspot.com/2011/02/uranus-is-seventh-planet-from-sun-and.html">Uranus</a> 2,870,990 25559 8.69e25 </span><span style="font-family: inherit;"><br />
</span><span style="font-family: inherit;"><a href="http://oursolarsysteminfo.blogspot.com/2011/02/neptune.html">Neptune</a> 4,497,070 24764 1.02e26 </span><span style="font-family: inherit;"><br />
</span><span style="font-family: inherit;"><a href="http://oursolarsysteminfo.blogspot.com/2011/02/pluto.html">Pluto</a> 5,913,520 1160 1.31e22 </span><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhRZ4JQPs8C0MaTB_zV8YsiFzjZjKiPozDFBrEBn-Bf8S2UFk1H9HImYTAlkp63ner_LKgIT4q724ZHRnw9SGn-gIVtlZHC0RDvsOfgx6IGoQci-Nw3iZsGK0NcG1Imm7nMAuq6b28V01cn/s1600/sun.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="181" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhRZ4JQPs8C0MaTB_zV8YsiFzjZjKiPozDFBrEBn-Bf8S2UFk1H9HImYTAlkp63ner_LKgIT4q724ZHRnw9SGn-gIVtlZHC0RDvsOfgx6IGoQci-Nw3iZsGK0NcG1Imm7nMAuq6b28V01cn/s320/sun.jpg" width="320" /></a></div><br />
</div>Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-6092218064926085931.post-83663532248585269502011-03-08T21:52:00.000-08:002011-03-15T13:40:43.116-07:00MERCURY<div dir="ltr" style="text-align: left;" trbidi="on"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>Mercury is the closest planet to the Sun and the eighth largest. Mercury is slightly smaller in diameter than the moons </b></span><a href="http://nineplanets.org/ganymede.html"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>Ganymede</b></span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b> and </b></span><a href="http://nineplanets.org/titan.html"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>Titan</b></span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b> but more than twice as massive.</b></span><br />
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<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhN43xYDafqDEiUue-BBGN3gMcsDMaGfvowlPera-nK6ELDbARDOgq_4ChRtkFxuKo54oFjOrM06C480QMGWZXuSBlJPd6CD_CphRCG-o84e0Xv831s3roS9I6R19SIFKNvhWrIA_hklLqd/s1600/mercury.jpg" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhN43xYDafqDEiUue-BBGN3gMcsDMaGfvowlPera-nK6ELDbARDOgq_4ChRtkFxuKo54oFjOrM06C480QMGWZXuSBlJPd6CD_CphRCG-o84e0Xv831s3roS9I6R19SIFKNvhWrIA_hklLqd/s320/mercury.jpg" width="320" /></a></div><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b> </b></span><a href="http://nineplanets.org/data.html"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b><span style="color: blue;">orbit</span></b></span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>: 57,910,000 km (0.38 </b></span><a href="http://nineplanets.org/help.html#au"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>AU</b></span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>) from Sun</b></span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b><br />
</b></span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b> </b></span><a href="http://nineplanets.org/data1.html"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b><span style="color: blue;">diameter</span></b></span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>: 4,880 km</b></span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b><br />
</b></span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b> </b></span><a href="http://nineplanets.org/data1.html"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b> <span style="color: blue;">mass</span></b></span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>: 3.30e23 kg</b></span><br />
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<span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>In Roman mythology </b></span><a href="http://oursolarsysteminfo.blogspot.com/2011/03/mercury.html"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>Mercury</b></span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b> is the god of commerce, travel and thievery, the Roman counterpart of the Greek god </b></span><a href="http://www.pantheon.org/articles/h/hermes.html"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>Hermes</b></span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>, the messenger of the Gods. The planet probably received this name because it moves so quickly across the sky. </b></span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b><br />
</b></span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b><br />
</b></span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>Mercury has been known since at least the time of the Sumerians (3rd millennium BC). It was sometimes given separate names for its apparitions as a morning star and as an evening star. Greek astronomers knew, however, that the two names referred to the same body. Heraclitus even believed that Mercury and Venus orbit the Sun, not the Earth. </b></span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b><br />
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</b></span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>Since it is closer to the Sun than the Earth, the illumination of Mercury's disk varies when viewed with a telescope from our perspective. </b></span><a href="http://nineplanets.org/help.html#galileo"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>Galileo's</b></span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b> telescope was too small to see Mercury's phases but he did see the phases of </b></span><a href="http://oursolarsysteminfo.blogspot.com/2011/03/venus.html"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>Venus</b></span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>. </b></span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b><br />
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</b></span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>Mercury has been now been visited by two spacecraft, </b></span><a href="http://nineplanets.org/spacecraft.html#marin10"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>Mariner 10</b></span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b> and </b></span><a href="http://messenger.jhuapl.edu/index.php"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>MESSENGER</b></span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>. Marriner 10 flew by three times in 1974 and 1975. Only 45% of the surface was mapped (and, unfortunately, it is too close to the Sun to be safely imaged by </b></span><a href="http://nineplanets.org/spacecraft.html#hst"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>HST). MESSENGER</b></span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b> was launched by NASA in 2004 and will orbit Mercury starting in 2011 after several flybys. Its first flyby in Jan 2008 provided new high quality</b></span><a href="http://messenger.jhuapl.edu/gallery/sciencePhotos/view.php?gallery_id=2"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b> images</b></span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b> of some of the terrain not seen by Marriner 10. </b></span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b><br />
</b></span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b><br />
</b></span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>Mercury's orbit is highly eccentric; at </b></span><a href="http://nineplanets.org/help.html#perihelion"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>perihelion</b></span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b> it is only 46 million km from the Sun but at </b></span><a href="http://nineplanets.org/help.html#aphelion"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>aphelion</b></span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b> it is 70 million. The position of the perihelion precesses around the Sun at a very slow rate. 19th century astronomers made very careful observations of Mercury's orbital parameters but could not adequately explain them using </b></span><a href="http://nineplanets.org/help.html#newton"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>Newtonian</b></span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b> mechanics. The tiny differences between the observed and predicted values were a minor but nagging problem for many decades. It was thought that another planet (sometimes called </b></span><a href="http://nineplanets.org/hypo.html#vulcan"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>Vulcan</b></span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>) slightly closer to the Sun than Mercury might account for the discrepancy. But despite much effort, no such planet was found. The real answer turned out to be much more dramatic: </b></span><a href="http://nineplanets.org/help.html#einstein"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>Einstein's</b></span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b> </b></span><a href="http://nineplanets.org/help.html#relativity"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>General Theory of Relativity</b></span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>! Its correct prediction of the motions of Mercury was an important factor in the early acceptance of the theory. </b></span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b><br />
</b></span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b><br />
</b></span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>Until 1962 it was thought that Mercury's "day" was the same length as its "year" so as to keep that same face to the Sun much as the Moon does to the Earth. But this was shown to be false in 1965 by doppler radar observations. It is now known that Mercury rotates three times in two of its years. Mercury is the only body in the solar system known to have an orbital/rotational resonance with a ratio other than 1:1 (though many have no </b></span><a href="http://nineplanets.org/help.html#resonance"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>resonances</b></span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b> at all). </b></span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b><br />
</b></span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b><br />
</b></span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>This fact and the high eccentricity of Mercury's orbit would produce very strange effects for an observer on Mercury's surface. At some longitudes the observer would see the Sun rise and then gradually increase in apparent size as it slowly moved toward the zenith. At that point the Sun would stop, briefly reverse course, and stop again before resuming its path toward the horizon and decreasing in apparent size. All the while the stars would be moving three times faster across the sky. Observers at other points on Mercury's surface would see different but equally bizarre motions. </b></span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b><br />
</b></span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b><br />
</b></span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>Temperature variations on Mercury are the most extreme in the solar system ranging from 90 K to 700 K. The temperature on </b></span><a href="http://oursolarsysteminfo.blogspot.com/2011/03/venus.html"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>Venus</b></span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b> is slightly hotter but very stable. </b></span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b><br />
</b></span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b><br />
</b></span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b> Mercury is in many ways similar to the Moon: its surface is heavily cratered and very </b></span><a href="http://nineplanets.org/luna.html"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>old</b></span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>; it has no </b></span><a href="http://nineplanets.org/help.html#old"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>plate tectonics</b></span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>. On the other hand, Mercury is much denser than the Moon (5.43 gm/cm3 vs 3.34). Mercury is the second </b></span><a href="http://nineplanets.org/datamax.html#densest"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>densest</b></span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b> major body in the solar system, after </b></span><a href="http://oursolarsysteminfo.blogspot.com/2011/02/earth.html"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>Earth</b></span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>. Actually Earth's density is due in part to gravitational compression; if not for this, Mercury would be denser than Earth. This indicates that Mercury's dense iron core is relatively larger than Earth's, probably comprising the majority of the planet. Mercury therefore has only a relatively thin </b></span><a href="http://nineplanets.org/help.html#silicate"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>silicate</b></span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b> mantle and crust. </b></span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b><br />
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</b></span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>Mercury's interior is dominated by a large iron core whose radius is 1800 to 1900 km. The silicate outer shell (analogous to Earth's mantle and crust) is only 500 to 600 km thick. At least some of the core is probably molten. </b></span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b><br />
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</b></span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>Mercury actually has a very thin atmosphere consisting of atoms blasted off its surface by the </b></span><a href="http://nineplanets.org/sol.html#solarwind"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>solar wind</b></span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>. Because Mercury is so hot, these atoms quickly escape into space. Thus in contrast to the Earth and Venus whose atmospheres are stable, Mercury's atmosphere is constantly being replenished. </b></span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b><br />
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</b></span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b> The surface of Mercury exhibits enormous escarpments, some up to hundreds of kilometers in length and as much as three kilometers high. Some cut thru the rings of craters and other features in such a way as to indicate that they were formed by compression. It is estimated that the surface area of Mercury shrank by about 0.1% (or a decrease of about 1 km in the planet's radius). </b></span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b><br />
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</b></span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>One of the largest features on Mercury's surface is the Caloris Basin (right); it is about 1300 km in diameter. It is thought to be similar to the large basins (maria) Weird terrain opposite Caloris Basin </b></span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b><br />
</b></span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>on the </b></span><a href="http://nineplanets.org/luna.html"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>Moon</b></span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>. Like the lunar basins, it was probably caused by a very large impact early in the history of the solar system. That impact was probably also responsible for the odd terrain on the exact opposite side of the planet (left). </b></span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b><br />
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</b></span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>In addition to the heavily cratered terrain, Mercury also has regions of relatively smooth plains. Some may be the result of ancient volcanic activity but some may be the result of the deposition of ejecta from cratering impacts. </b></span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b><br />
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</b></span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>A </b></span><a href="http://www.psrd.hawaii.edu/Jan97/MercuryUnveiled.html"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>reanalysis</b></span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b> of the Mariner data provides some preliminary evidence of recent volcanism on Mercury. But more data will be needed for confirmation. </b></span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b><br />
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</b></span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>Amazingly, radar observations of Mercury's north pole (a region not mapped by Mariner 10) show evidence of water ice in the protected shadows of some craters. </b></span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b><br />
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</b></span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>Mercury has a small magnetic field whose strength is about 1% of Earth's. </b></span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b><br />
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</b></span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>Mercury has no known satellites. </b></span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b><br />
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</b></span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>Mercury is often </b></span><a href="http://nineplanets.org/see.html"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>visible </b></span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>with binoculars or even the unaided eye, but it is always very near the Sun and difficult to see in the twilight sky. There are several </b></span><a href="http://astro.nineplanets.org/astrosoftware.html#www"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>Web sites</b></span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b> that show the current position of Mercury (and the other planets) in the sky. More detailed and customized charts can be created with a </b></span><a href="http://astro.nineplanets.org/astrosoftware.html"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>planetarium program</b></span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>.</b></span><br />
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</div>Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-6092218064926085931.post-30174907668256196032011-03-06T19:05:00.000-08:002011-03-15T13:42:57.121-07:00VENUS<div dir="ltr" style="text-align: left;" trbidi="on"><div align="left"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Venus is the second planet from the </span></b><a href="http://oursolarsysteminfo.blogspot.com/2011/03/sun.html"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Sun</span></b></a><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> and the sixth largest. Venus' orbit is the most nearly circular of that of any planet, with an eccentricity of less than 1%.</span></b><br />
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<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhmP-XVFBCOlFHWF3vV08lrMYUXT07x0IkPVMDxcztVQSOf3TT2Hhhq64Ky8Apirwrbxo7JrFbSpxCM0mtzSIeVPJMJC4DI3JlDotlfts_U_8bw412q0eJdY81KB91om6mMsKzFwFAyHCLa/s1600/VENUS.jpg" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhmP-XVFBCOlFHWF3vV08lrMYUXT07x0IkPVMDxcztVQSOf3TT2Hhhq64Ky8Apirwrbxo7JrFbSpxCM0mtzSIeVPJMJC4DI3JlDotlfts_U_8bw412q0eJdY81KB91om6mMsKzFwFAyHCLa/s320/VENUS.jpg" width="297" /></a></div><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> <a href="http://nineplanets.org/data.html"> orbit</a>: 108,200,000 km (0.72 <a href="http://nineplanets.org/help.html">AU</a>) from Sun<br />
<a href="http://nineplanets.org/data1.html">diameter</a>: 12,103.6 km<br />
<a href="http://nineplanets.org/data1.html">mass</a>: 4.869e24 kg<br />
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</span></b></div><div align="left"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> </span></b><a href="http://oursolarsysteminfo.blogspot.com/2011/03/venus.html"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Venus</span></b></a><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> (Greek: </span></b><a href="http://www.pantheon.org/articles/a/aphrodite.html"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Aphrodite</span></b></a><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">; Babylonian: Ishtar) is the goddess of love and beauty. The planet is so named probably because it is the </span></b><a href="http://nineplanets.org/datamax.html#brightest"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">brightest</span></b></a><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> of the planets known to the ancients. (With a few exceptions, the surface features on Venus are named for female figures.) </span></b><br />
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<b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Venus has been known since prehistoric times. It is the brightest object in the sky except for the Sun and the Moon. Like </span></b><a href="http://oursolarsysteminfo.blogspot.com/2011/03/mercury.html"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Mercury</span></b></a><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">, it was popularly thought to be two separate bodies: Eosphorus as the morning star and Hesperus as the evening star, but the Greek astronomers knew better. (Venus's apparition as the morning star is also sometimes called Lucifer.) </span></b><br />
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<b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Since Venus is an </span></b><a href="http://nineplanets.org/overview.html#infsup"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">inferior </span></b></a><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">planet, it shows </span></b><a href="http://www.badastronomy.com/bitesize/venus_phase.html"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">phases</span></b></a><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> when viewed with a telescope from the perspective of Earth. Galileo's observation of this phenomenon was important evidence in favor of </span></b><a href="http://nineplanets.org/help.html#copernicus"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Copernicus's</span></b></a><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> </span></b><a href="http://nineplanets.org/help.html#heliocentric"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">heliocentric</span></b></a><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> theory of the solar system. </span></b><br />
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<b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">The first spacecraft to visit Venus was </span></b><a href="http://nineplanets.org/spacecraft.html#marin2"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Mariner</span></b></a><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> 2 in 1962. It was subsequently visited by many others (more than 20 in all so far), including </span></b><a href="http://nineplanets.org/spacecraft.html#pioneervenus"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Pioneer Venus</span></b></a><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> and the Soviet </span></b><a href="http://nineplanets.org/spacecraft.html#venera7"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Venera 7</span></b></a><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> the first spacecraft to land on another planet, and </span></b><a href="http://nineplanets.org/spacecraft.html#venera9"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Venera 9</span></b></a><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> which returned the first photographs of the surface. The </span></b><a href="http://nineplanets.org/spacecraft.html#magellan"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Magellan</span></b></a><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> radar map (false color) </span></b><br />
<b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">first orbiter, the US spacecraft Magellan Magellan radar map (false color) produced detailed maps of Venus' surface using radar. ESA's </span></b><a href="http://www.esa.int/SPECIALS/Venus_Express/SEMBD3808BE_0.html"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Venus Express</span></b></a><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> is now in orbit with a large </span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">variety of instruments. </span></b><br />
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<b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Venus' rotation is somewhat unusual in that it is both very slow (243 Earth days per Venus day, slightly longer than Venus' year) and </span></b><a href="http://nineplanets.org/help.html#retrograde"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">retrograde</span></b></a><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">. In addition, the periods of Venus' rotation and of its orbit are synchronized such that it always presents the same face toward Earth when the two planets are at their closest approach. Whether this is a resonance effect or merely a coincidence is not known. </span></b><br />
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<b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Venus is sometimes regarded as </span></b><a href="http://oursolarsysteminfo.blogspot.com/2011/02/earth.html"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Earth's</span></b></a><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> sister planet. In some ways they are very similar: </span></b><br />
<ul style="text-align: left;"><li style="text-align: left;"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> Venus is only slightly smaller than Earth (95% of Earth's diameter, 80% of Earth's mass). </span></b></li>
</ul><ul style="text-align: left;"><li><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> Both have few craters indicating relatively </span></b><a href="http://nineplanets.org/help.html#young"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">young</span></b></a><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> surfaces. </span></b></li>
</ul><ul style="text-align: left;"><li><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> Their densities and chemical compositions are similar. </span></b></li>
</ul><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Because of these similarities, it was thought that below its dense clouds Venus might be very Earthlike and might even have life. But, unfortunately, more detailed study of Venus reveals that in many important ways it is radically different from Earth. It may be the least hospitable place for life in the solar system. </span></b><br />
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<b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">The pressure of Venus' atmosphere at the surface is 90 atmospheres (about the same as the pressure at a depth of 1 km in Earth's oceans). It is composed mostly of carbon dioxide. There are several layers of clouds many kilometers thick composed of sulfuric acid. These clouds completely obscure our view of the surface. This dense atmosphere produces a run-away </span></b><a href="http://nineplanets.org/help.html#greenhouse"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">greenhouse effect</span></b></a><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> that raises Venus' surface temperature by about 400 degrees to over 740 K (hot enough to melt lead). Venus' surface is actually hotter than </span></b><a href="http://oursolarsysteminfo.blogspot.com/2011/03/mercury.html"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Mercury's</span></b></a><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> despite being nearly twice as far from the Sun. </span></b><br />
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<b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">There are strong (350 kph) winds at the cloud tops but winds at the surface are very slow, no more than a few kilometers per hour. </span></b><br />
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<b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Venus probably once had large amounts of water like Earth but it all boiled away. Venus is now quite dry. Earth would have suffered the same fate had it been just a little closer to the Sun. We may learn a lot about Earth by learning why the basically similar Venus turned out so differently. </span></b><br />
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<b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Most of Venus' surface consists of gently rolling plains with little relief. There are also several broad depressions: </span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><span style="color: purple;">Atalanta Planitia</span></span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">, <span style="color: purple;">Guinevere Planitia</span>, <span style="color: purple;">Lavinia Planitia</span>. There two large highland areas: <span style="color: purple;">Ishtar Terra</span> in the northern hemisphere (about the size of Australia) and <span style="color: purple;">Aphrodite Terra</span> along the equator (about the size of South America). The interior of Ishtar consists mainly of a high plateau, <span style="color: purple;">Lakshmi Planum</span>, which is surrounded by the highest mountains on Venus including the enormous <span style="color: purple;">Maxwell Montes.</span></span></b></div><div align="left"></div><div align="center"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> </span></b></div><div align="center"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> </span></b></div><div align="center"><a href="http://www.videojug.com/film/all-about-venus"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"></span></b></a></div></div>Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-6092218064926085931.post-64153454352881007302011-02-24T11:56:00.000-08:002011-03-15T13:44:24.350-07:00EARTH<div dir="ltr" style="text-align: left;" trbidi="on"><br />
<div class="MsoNormal"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg_lf__vVfWZZ3pI-G1IJfwNKy6mXgfSKLuIqP6_ArSkvq6wzBC7CPRphaYuxg3dVUc6-TR-l5iYKfgiCxhQZNHONXmLoDsaCgZJXWU5yff8rVmrwgfJXtLP_wSAOntRzB4hwudmh5TeGtF/s1600/bluemarblewest.jpg" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg_lf__vVfWZZ3pI-G1IJfwNKy6mXgfSKLuIqP6_ArSkvq6wzBC7CPRphaYuxg3dVUc6-TR-l5iYKfgiCxhQZNHONXmLoDsaCgZJXWU5yff8rVmrwgfJXtLP_wSAOntRzB4hwudmh5TeGtF/s1600/bluemarblewest.jpg" /></a><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Earth is the third planet from the Sun and the fifth largest: </span></b></div><div class="MsoNormal"><br />
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<div align="left" class="MsoNormal"><span style="mso-spacerun: yes;"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> </span></b></span><a href="http://nineplanets.org/data.html"><span style="color: #351c75;"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">orbit:</span></b></span></a><span style="color: #351c75;"><span style="mso-spacerun: yes;"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> </span></b></span></span><span style="mso-spacerun: yes;"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> </span></b></span><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><span style="color: #38761d;">149,600,000 km (1.00 <a href="http://nineplanets.org/help.html#au">AU</a>) from Sun</span></span></b></div><div align="left"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> </span></b></div><div align="left" class="MsoNormal"><span style="mso-spacerun: yes;"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> </span></b></span><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><a href="http://nineplanets.org/data1.html"><span style="color: #351c75;">diameter</span></a></span></b><span style="color: #674ea7;"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">:</span></b></span><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><span style="color: #351c75;"> </span></span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><span style="color: #674ea7;"> </span><span style="color: #38761d;">12,756.3 km</span></span></b></div><div align="left"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> </span></b></div><div align="left" class="MsoNormal"><span style="mso-spacerun: yes;"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> </span></b></span><a href="http://nineplanets.org/data1.html"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><span style="color: #351c75;">mass:</span></span></b></a><span style="mso-spacerun: yes;"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> </span></b></span><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><span style="color: #38761d;">5.972e24 kg</span></span></b><br />
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</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Earth is the only planet whose English name does not derive from Greek/Roman mythology. The name derives from Old English and Germanic. There are, of course, hundreds of other names for the planet in <a href="http://nineplanets.org/days.html">other languages</a>. In Roman Mythology, the goddess of the Earth was <a href="http://www.pantheon.org/articles/t/tellus.html">Tellus</a> - the fertile soil (Greek: <a href="http://www.pantheon.org/articles/g/gaia.html">Gaia</a>, terra mater - Mother Earth). </span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
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</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">It was not until the time of <a href="http://nineplanets.org/help.html#copernicus">Copernicus</a> (the sixteenth century) that it was understood that the Earth is just another planet. </span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
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</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Earth, of course, can be studied without the aid of spacecraft. Nevertheless it was not until the twentieth century that we had maps of the entire planet. Pictures of the planet taken from space are of considerable importance; for example, they are an enormous help in weather prediction and especially in tracking and predicting hurricanes. And they are extraordinarily beautiful. </span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
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</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">The Earth is divided into several layers which have distinct chemical and seismic properties (depths in km): </span></b></div><br />
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<div class="MsoNormal"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> </span></b><span style="color: #38761d;"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> 0-</span></b><span style="mso-spacerun: yes;"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> </span></b></span><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">40</span></b></span><span style="mso-spacerun: yes;"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> </span></b></span><span style="color: #351c75;"><span style="mso-spacerun: yes;"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> </span></b></span><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Crust</span></b></span></div><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> </span></b><br />
<div class="MsoNormal"><span style="mso-tab-count: 1;"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> </span></b></span><span style="mso-spacerun: yes;"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> </span></b></span><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><span style="color: #38761d;">40- 400</span></span></b><span style="mso-spacerun: yes;"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> </span></b></span><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><span style="color: #351c75;">Upper mantle</span></span></b></div><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> </span></b><br />
<div class="MsoNormal"><span style="mso-tab-count: 1;"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> </span></b></span><span style="mso-spacerun: yes;"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> </span></b></span><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><span style="color: #38761d;">400- 650</span> </span></b><span style="mso-spacerun: yes;"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> </span></b></span><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><span style="color: #351c75;">Transition region</span></span></b></div><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> </span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> </span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> </span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">The crust varies considerably in thickness, it is thinner under the oceans, thicker under the continents. The inner core and crust are solid; the outer core and mantle layers are plastic or semi-fluid. The various layers are separated by discontinuities which are evident in seismic data; the best known of these is the <a href="http://www.geolsoc.org.uk/index.html">Mohorovicic</a> <a href="http://www.seismo.unr.edu/ftp/pub/louie/class/plate/velocity.html">discontinuity</a> between the crust and upper mantle. </span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
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</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Most of the mass of the Earth is in the mantle, most of the rest in the core; the part we inhabit is a tiny fraction of the whole (values below x10^24 kilograms):</span></b><br />
<b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> </span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> <span style="color: #351c75;"> atmosphere </span> = <span style="color: #38761d;">0.0000051</span></span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><span style="color: #351c75;"> oceans </span> = <span style="color: #38761d;">0.0014</span></span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> <span style="color: #351c75;"> crust </span> = <span style="color: #38761d;">0.026</span></span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> <span style="color: #351c75;">mantle </span> = <span style="color: #38761d;">4.043</span></span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> <span style="color: #351c75;"> outer core </span> = <span style="color: #38761d;">1.835</span></span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> <span style="color: #351c75;"> inner core </span> = <span style="color: #38761d;">0.09675</span></span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
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</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">The core is probably composed mostly of iron (or nickel/iron) though it is possible that some lighter elements may be present, too. Temperatures at the center of the core may be as high as 7500 K, hotter than the surface of the <a href="http://oursolarsysteminfo.blogspot.com/2011/03/sun.html">Sun</a>. The lower mantle is probably mostly silicon, magnesium and oxygen with some iron, calcium and aluminum. The upper mantle is mostly olivene and pyroxene (iron/magnesium <a href="http://nineplanets.org/help.html#silicate">silicates</a>), calcium and aluminum. We know most of this only from seismic techniques; samples from the upper mantle arrive at the surface as lava from volcanoes but the majority of the Earth is inaccessible. The crust is primarily quartz (silicon dioxide) and other silicates like feldspar. Taken as a whole, the Earth's chemical composition (by mass) is: </span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> </span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> <span style="color: #38761d;">34.6%</span> <a href="http://pearl1.lanl.gov/periodic/elements/26.html">Iron</a></span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> <span style="color: #38761d;">29.5%</span> <a href="http://www.chemicalelements.com/elements/o.html"> Oxygen</a></span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> <span style="color: #38761d;">15.2%</span> <a href="http://www.chemicool.com/elements/silicon.html">Silicon</a></span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> <span style="color: #38761d;">12.7%</span> <a href="http://www.rsc.org/chemsoc/visualelements/pages/magnesium.html">Magnesium</a></span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> <span style="color: #38761d;">2.4%</span> <a href="http://chemlab.pc.maricopa.edu/periodic/Ni.html">Nickel</a></span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> <span style="color: #38761d;">1.9% </span> <a href="http://www.webelements.com/sulfur/">Sulfur</a> </span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> <span style="color: #38761d;">0.05%</span> <a href="http://www.webelements.com/titanium/"> Titanium</a></span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
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</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">The Earth is the densest major body in the solar system.</span></b><br />
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<b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> <span style="color: #351c75;"> Distance Radius Mass</span><br />
<span style="color: #351c75;">Satellite</span> <span style="color: #3d85c6;">(000 km) (km) (kg)</span><br />
--------- -------- ------ -------<br />
<span style="color: #b45f06;">Moon</span> <span style="color: #38761d;">384 1738 7.35e22 </span><br />
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</span></b></div></div>Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-6092218064926085931.post-38109830611200636262011-02-23T10:25:00.000-08:002011-02-23T10:25:36.465-08:00MARS VIDEO<div dir="ltr" style="text-align: left;" trbidi="on"><div class="separator" style="clear: both; text-align: center;"></div><div class="separator" style="clear: both; text-align: center;"></div><div class="separator" style="clear: both; text-align: center;"></div><div class="separator" style="clear: both; text-align: center;"></div><div class="separator" style="clear: both; text-align: center;"><br />
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</div>Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-6092218064926085931.post-3891278450566738672011-02-23T10:07:00.000-08:002011-03-15T13:45:25.829-07:00MARS<div dir="ltr" style="text-align: left;" trbidi="on"><div class="separator" style="clear: both; text-align: center;"></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjSHI7cACKDQThv8dUhgrKvl5rGxs8JOI1msenPk8a6s0a2ERnObZvSMKlI9z-SFhHFHWMQ9v1HOgY963yI39yVPG02BCrH9o-BbvUJLjve3Q6XmWd9VCrBx0xpf13sCmz4FMaOfP-91LIC/s1600/mars_hst_big.jpg" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjSHI7cACKDQThv8dUhgrKvl5rGxs8JOI1msenPk8a6s0a2ERnObZvSMKlI9z-SFhHFHWMQ9v1HOgY963yI39yVPG02BCrH9o-BbvUJLjve3Q6XmWd9VCrBx0xpf13sCmz4FMaOfP-91LIC/s320/mars_hst_big.jpg" width="256" /></a></div><a href="http://4.bp.blogspot.com/-BdZNnilT-Mw/TWVMmJxg_QI/AAAAAAAAAFM/s1600/mars_hst_big.jpg" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><br />
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<b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><a href="http://oursolarsysteminfo.blogspot.com/2011/02/mars.html"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Mars</span></b></a><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> (Greek: </span></b><a href="http://www.pantheon.org/articles/a/ares.html"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Ares</span></b></a><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">) is the god of War. The planet probably got this name due to its red color; Mars is sometimes referred to as the Red Planet. (An interesting side note: the Roman god Mars was a god of agriculture before becoming associated with the Greek Ares; those in favor of colonizing and terraforming Mars may prefer this symbolism.) The name of the </span></b><a href="http://nineplanets.org/days.html#months"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">month</span></b></a><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> March derives from Mars. </span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Mars has been known since prehistoric times. Of course, it has been extensively studied with ground-based </span></b><a href="http://astro.nineplanets.org/bigeyes.html"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">observatories</span></b></a><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">. But even very large telescopes find Mars a difficult target, it's just too small. It is still a favorite of </span></b><a href="http://nineplanets.org/mars.html#sf"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">science fiction</span></b></a><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> writers as the most favorable place in the Solar System (other than Earth!) for human habitation. But the famous "canals" "seen" by </span></b><a href="http://nineplanets.org/help.html#lowell"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Lowell</span></b></a><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> and others were, unfortunately, just as imaginary as </span></b><a href="http://nineplanets.org/help.html#barsoom"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Barsoomian</span></b></a><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> princesses. </span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
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</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">The first spacecraft to visit Mars was </span></b><a href="http://nineplanets.org/spacecraft.html#marin4"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Mariner 4</span></b></a><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> in 1965. Several others followed including </span></b><a href="http://nssdc.gsfc.nasa.gov/nmc/masterCatalog.do?sc=1971-045A"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Mars 2</span></b></a><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">, the first spacecraft to land on Mars and the two </span></b><a href="http://nineplanets.org/spacecraft.html#viking"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Viking</span></b></a><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> landers in 1976. Ending a long 20 year hiatus, </span></b><a href="http://nineplanets.org/spacecraft.html#pathfinder"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Mars Pathfinder</span></b></a><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> landed successfully on Mars on 1997 July 4. In 2004 the </span></b><a href="http://www.jpl.nasa.gov/missions/mer/"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Mars Expedition Rovers </span></b></a><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">"Spirit" and "Opportunity" landed on Mars sending back geologic data and many pictures; they are still operating after more than three years on Mars. In 2008, </span></b><a href="http://www.jpl.nasa.gov/missions/missiondetails.cfm?mission=Phoenix"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Phoenix</span></b></a><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> landed in the northern plains to search for water. Three Mars orbiters (</span></b><a href="http://marsprogram.jpl.nasa.gov/mro/"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Mars Reconnaissance Orbiter</span></b></a><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">, </span></b><a href="http://mars.jpl.nasa.gov/odyssey/index.cfm"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Mars Odyssey</span></b></a><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">, and </span></b><a href="http://www.esa.int/SPECIALS/Mars_Express/"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Mars Express</span></b></a><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">) are also currently in operation. </span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
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</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Mars' orbit is significantly elliptical. One result of this is a temperature variation of about 30 C at the subsolar point between aphelion and perihelion. This has a major influence on </span></b><a href="http://physics.anu.edu.au/404page.php"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Mars' climate</span></b></a><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">. While the average temperature on Mars is about 218 K (-55 C, -67 F), Martian surface temperatures range widely from as little as 140 K (-133 C, -207 F) at the winter pole to almost 300 K (27 C, 80 F) on the day side during summer. </span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
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</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Though Mars is much smaller than Earth, its surface area is about the same as the land surface area of Earth. </span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Olympus Mons </span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Mars has some of the most highly varied and interesting terrain of any of the </span></b><a href="http://nineplanets.org/overview.html#ter_p"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">terrestrial</span></b></a><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> planets, some of it quite spectacular: </span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><span style="color: #0b5394;"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Olympus Mons:</span></b></span><span style="color: #45818e;"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> </span></b></span><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">the largest mountain in the Solar System rising 24 km (78,000 ft.) above the surrounding plain. Its base is more than 500 km in diameter and is rimmed by a cliff 6 km (20,000 ft) high. </span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><span style="color: #0b5394;"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Tharsis:</span></b></span><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> a huge bulge on the Martian surface that is about 4000 km across and 10 km high. </span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><span style="color: #0b5394;"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Valles Marineris:</span></b></span><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> a system of canyons 4000 km long and from 2 to 7 km deep (top of page); </span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b><br />
<div style="text-align: left;"><span style="color: #0b5394;"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Hellas Planitia</span></b></span><span style="color: #45818e;"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">: </span></b></span><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">an impact crater in the southern hemisphere over 6 km deep and 2000 km in diameter. </span></b><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span></b></div><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Much of the Martian surface is very </span></b><a href="http://nineplanets.org/help.html#old"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">old</span></b></a><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> and cratered, but there are also much younger rift valleys, ridges, hills and plains. (None of this is visible in any detail with a telescope, even the Hubble Space Telescope; all this information comes from the spacecraft that we've sent to Mars.)</span></b></div>Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-6092218064926085931.post-35226583748382782032011-02-23T09:53:00.000-08:002011-02-23T09:53:23.319-08:00LEARN ABOUT JUPITER<div dir="ltr" style="text-align: left;" trbidi="on"><div class="separator" style="clear: both; text-align: center;"><iframe allowfullscreen='allowfullscreen' webkitallowfullscreen='webkitallowfullscreen' mozallowfullscreen='mozallowfullscreen' width='320' height='266' src='https://www.blogger.com/video.g?token=AD6v5dw2AdRyVufF-Lx25zjrCEnBE-5OKY5fixJ3WD1VufkO7lpe5Ldls5zjvMdW43bMOcduIKNMAxOBoJ9z6pDWuA' class='b-hbp-video b-uploaded' frameborder='0'></iframe></div><a href="http://video.answers.com/learn-about-jupiter-38356644">http://video.answers.com/learn-about-jupiter-38356644</a></div>Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-6092218064926085931.post-31377554841382022692011-02-23T08:58:00.000-08:002011-03-15T18:27:12.593-07:00JUPITER<div dir="ltr" style="text-align: left;" trbidi="on"><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgt6n-IFewDSMclzO0NCJH5__hLzdhXpcfDyBIkLpyQBdztfYBBVL-i89AZ8WxCus4b6UYpzycBiBwTZHAKmNlfcia-fWvQpSmKaUF2LRceSc92jtDLA99j4nC784o8WYfFEXgaouZtYwCq/s1600/redspot.jpg" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgt6n-IFewDSMclzO0NCJH5__hLzdhXpcfDyBIkLpyQBdztfYBBVL-i89AZ8WxCus4b6UYpzycBiBwTZHAKmNlfcia-fWvQpSmKaUF2LRceSc92jtDLA99j4nC784o8WYfFEXgaouZtYwCq/s1600/redspot.jpg" /></a></div><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Jupiter</span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> (a.k.a. Jove; Greek </span><a href="http://www.pantheon.org/articles/z/zeus.html"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Zeus</span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">) was the King of the Gods, the ruler of Olympus and the patron of the Roman state. Zeus was the son of </span><a href="http://www.pantheon.org/articles/c/cronus.html"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Cronus</span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> (Saturn). </span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Jupiter is the fourth </span><a href="http://nineplanets.org/datamax.html#brightest"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">brightest</span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> object in the sky (after the</span><a href="http://oursolarsysteminfo.blogspot.com/2011/03/sun.html"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> Sun</span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">, the </span><a href="http://nineplanets.org/luna.html"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Moon</span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> and </span><a href="http://nineplanets.org/venus.html"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Venus</span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">). It has been known since prehistoric times as a bright "wandering star". But in 1610 when </span><a href="http://nineplanets.org/help.html#galileo"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Galileo</span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> first pointed a telescope at the sky he </span><a href="http://galileo.rice.edu/science.html/jupiter_satellites.html"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">discovered</span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> Jupiter's four large moons </span><a href="http://nineplanets.org/io.html"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Io</span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">, </span><a href="http://nineplanets.org/europa.html"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Europa</span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">, </span><a href="http://nineplanets.org/ganymede.html"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Ganymede</span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> and </span><a href="http://nineplanets.org/callisto.html"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Callisto</span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> (now known as the </span><span style="background-color: orange;"><span style="background-color: #6fa8dc;"><b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Galilean</span></b></span></span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> moons) and recorded their motions back and forth around Jupiter. This was the first </span><a href="http://solarsystem.nasa.gov/galileo/"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">discovery</span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> of a center of motion not apparently centered on the Earth. It was a major point in favor of </span><a href="http://nineplanets.org/help.html#copernicus"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Copernicus</span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">'s </span><a href="http://nineplanets.org/help.html#heliocentric"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">heliocentric</span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> theory of the motions of the planets (along with other new evidence from his telescope: the phases of </span><a href="http://oursolarsysteminfo.blogspot.com/2011/03/venus.html"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Venus</span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> and the mountains on the </span><a href="http://nineplanets.org/luna.html"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Moon</span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">). Galileo's outspoken support of the Copernican theory got him in trouble with the </span><a href="http://nineplanets.org/help.html#inquisition"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Inquisition</span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">. Today anyone can repeat Galileo's observations (without fear of retribution :-) using binoculars or an inexpensive telescope. </span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Jupiter was first visited by </span><a href="http://nineplanets.org/spacecraft.html#pioneer10"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Pioneer 10</span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> in 1973 and later by </span><a href="http://nineplanets.org/spacecraft.html#pioneer11"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Pioneer 11</span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">, </span><a href="http://nineplanets.org/spacecraft.html#Voyager1"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Voyager 1</span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">, </span><a href="http://nineplanets.org/spacecraft.html#Voyager2"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Voyager 2</span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> and </span><a href="http://nineplanets.org/spacecraft.html#ulysses"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Ulysses</span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">. The spacecraft </span><a href="http://nineplanets.org/help.html#galileo"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Galileo</span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> orbited Jupiter for eight years. It is still regularly observed by the </span><a href="http://nineplanets.org/spacecraft.html#hst"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Hubble Space Telescope. </span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">The </span><a href="http://nineplanets.org/overview.html#gas_p"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">gas planets</span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> do not have solid surfaces, their gaseous material simply gets denser with depth (the radii and diameters quoted for the planets are for levels corresponding to a pressure of 1 atmosphere). What we see when looking at these planets is the tops of clouds high in their </span><a href="http://nineplanets.org/help.html#atm"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">atmospheres</span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> (slightly above the 1 atmosphere level). </span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Jupiter is about 90% </span><a href="http://cst.lanl.gov/CST/imagemap/periodic/1.html"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">hydrogen</span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> and 10% </span><a href="http://cst.lanl.gov/CST/imagemap/periodic/2.html"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">helium</span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> (by numbers of atoms, 75/25% by mass) with traces of methane, water, ammonia and "rock". This is very close to the composition of the primordial </span><a href="http://nineplanets.org/origin.html"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Solar Nebula</span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> from which the entire solar system was formed. </span><a href="http://oursolarsysteminfo.blogspot.com/2011/02/saturn.html"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Saturn</span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> has a similar composition, but </span><a href="http://oursolarsysteminfo.blogspot.com/2011/02/uranus-is-seventh-planet-from-sun-and.html"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Uranus</span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> and </span><a href="http://oursolarsysteminfo.blogspot.com/2011/02/neptune.html"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Neptune</span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> have much less hydrogen and helium. </span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Our knowledge of the interior of Jupiter (and the other gas planets) is highly indirect and likely to remain so for some time. (The data from </span><a href="http://nineplanets.org/spacecraft.html#galileo"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Galileo's</span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> atmospheric </span><a href="http://spaceprojects.arc.nasa.gov/Space_Projects/galileo_probe/"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">probe</span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> goes down only about 150 km below the cloud tops.) </span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Jupiter probably has a core of rocky material amounting to something like 10 to 15 Earth-masses. </span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> </span><br />
<span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">The </span><b><span style="background-color: #6aa84f;"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Great Red Spot</span></span></b><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> (GRS) has been seen by Earthly observers for more than 300 years (its discovery is usually attributed to </span><a href="http://nineplanets.org/help.html#cassini"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Cassini</span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">, or Robert Hooke in the 17th century). The GRS is an oval about 12,000 by 25,000 km, big enough to hold two Earths. Other smaller but similar spots have been known for decades. Infrared observations and the direction of its rotation indicate that the GRS is a high-pressure region whose cloud tops are significantly higher and colder than the surrounding regions. Similar structures have been seen on Saturn and </span><a href="http://oursolarsysteminfo.blogspot.com/2011/02/neptune.html"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Neptune</span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">. It is not known how such structures can persist for so long.</span><br />
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<span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Jupiter has rings like Saturn's, but much fainter and smaller (right). They were totally unexpected and were only discovered when two of the Voyager 1 scientists insisted that after traveling 1 billion km it was at least worth a quick look to see if any rings might be present. Everyone else thought that the chance of finding anything was nil, but there they were. It was a major coup. They have since been </span><a href="http://apod.nasa.gov/apod/ap970205.html"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">imaged</span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> in the infra-red from ground-based </span><a href="http://astro.nineplanets.org/bigeyes.html"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">observatories</span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> and by </span><a href="http://www.jpl.nasa.gov/galileo/status980915.html"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Galileo</span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">. </span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><br />
</span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">Unlike Saturn's, Jupiter's rings are dark (</span><a href="http://nineplanets.org/help.html#albedo"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;">albedo</span></a><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> about .05). They're probably composed of very small grains of rocky material. Unlike Saturn's rings, they seem to contain no ice.</span><br />
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<div align="center"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b><span style="font-size: large;">Jupiter Statistics</span></b></span></div><div align="center"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b><br />
</b></span><span style="color: #6aa84f;"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>Mass (kg) 1900e+27 <br />
Mass (Earth = 1) 3.1794e+02<br />
Equatorial radius (km) 71,492<br />
Equatorial radius (Earth = 1) 1.1209e+01<br />
Mean density (gm/cm^3) 1.33<br />
Mean distance from the Sun (km) 778,330,000<br />
Mean distance from the Sun (Earth = 1) 5.2028<br />
Rotational period (days) 0.41354<br />
Orbital period (days) 4332.71<br />
Mean orbital velocity (km/sec) 13.07<br />
Orbital eccentricity 0.0483<br />
Tilt of axis (degrees) 3.13<br />
Orbital inclination (degrees) 1.308<br />
Equatorial surface gravity (m/sec^2) 22.88<br />
Equatorial escape velocity (km/sec) 59.56<br />
Visual geometric albedo 0.52<br />
Magnitude (Vo) -2.70<br />
Mean cloud temperature -121°C<br />
Atmospheric pressure (bars) 0.7<br />
Atmospheric composition <br />
Hydrogen </b></span></span><span style="color: #6aa84f;"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b>90%</b></span></span><span style="color: #6aa84f;"><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"><b><br />
Helium 10% </b></span></span><span style="font-family: "Helvetica Neue", "Arial", "Helvetica", sans-serif;"> </span></div></div>Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-6092218064926085931.post-55626559581163374702011-02-16T14:22:00.000-08:002011-03-15T18:28:07.920-07:00SATURN<div dir="ltr" style="text-align: left;" trbidi="on"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgRWKSM8FAWhvX5Jz0i2ndDojod49sncXA6XdspakewxgIaSRLxxhgdEGZ7jzHspce5BrXwOB_sURVVXX4vNK0T-D_Jht4JrhfurbwxXEjpmPJZ4sC8PHQZ1viJEpsYzpXUM6XYplQHYBhO/s1600/saturnPic1.jpg" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="248" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgRWKSM8FAWhvX5Jz0i2ndDojod49sncXA6XdspakewxgIaSRLxxhgdEGZ7jzHspce5BrXwOB_sURVVXX4vNK0T-D_Jht4JrhfurbwxXEjpmPJZ4sC8PHQZ1viJEpsYzpXUM6XYplQHYBhO/s320/saturnPic1.jpg" width="320" /></a><br />
Saturn is the sixth planet from the Sun and is the second largest in the solar system with an equatorial diameter of 119,300 kilometers (74,130 miles). Much of what is known about the planet is due to the <a href="http://www.solarviews.com/eng/voyager.htm">Voyager</a> explorations in 1980-81. Saturn is visibly flattened at the poles, a result of the very fast rotation of the planet on its axis. Its day is 10 hours, 39 minutes long, and it takes 29.5 Earth years to revolve about the Sun. The atmosphere is primarily composed of hydrogen with small amounts of helium and methane. Saturn is the only planet less dense than water (about 30 percent less). In the unlikely event that a large enough ocean could be found, Saturn would float in it. Saturn's hazy yellow hue is marked by broad atmospheric banding similar to, but fainter than, that found on <a href="http://oursolarsysteminfo.blogspot.com/2011/02/jupiter.html">Jupiter</a>. <br />
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The wind blows at high speeds on Saturn. Near the equator, it reaches velocities of 500 meters a second (1,100 miles an hour). The wind blows mostly in an easterly direction. The strongest winds are found near the equator and velocity falls off uniformly at higher latitudes. At latitudes greater than 35 degrees, winds alternate east and west as latitude increases. <br />
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Saturn's <a href="http://www.solarviews.com/eng/saturnrings.htm">ring system</a> makes the planet one of the most beautiful objects in the solar system. The rings are split into a number of different parts, which include the bright A and B rings and a fainter C ring. The ring system has various gaps. The most notable gap is the Cassini [kah-SEE-nee] Division, which separates the A and B rings. <a href="http://www.solarviews.com/eng/people.htm#cassini">Giovanni Cassini</a> discovered this division in 1675. The Encke [EN-kee] Division, which splits the A Ring, is named after Johann Encke, who discovered it in 1837. Space probes have shown that the main rings are really made up of a large number of narrow ringlets. The origin of the rings is obscure. It is thought that the rings may have been formed from larger moons that were shattered by impacts of comets and meteoroids. The ring composition is not known for certain, but the rings do show a significant amount of water. They may be composed of icebergs and/or snowballs from a few centimeters to a few meters in size. Much of the elaborate structure of some of the rings is due to the gravitational effects of nearby satellites. This phenomenon is demonstrated by the relationship between the F-ring and two small moons that shepherd the ring material. <br />
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Radial, spoke-like features in the broad B-ring were also found by the Voyagers. The features are believed to be composed of fine, dust-size particles. The spokes were observed to form and dissipate in the time-lapse images taken by the Voyagers. While electrostatic charging may create spokes by levitating dust particles above the ring, the exact cause of the formation of the spokes is not well understood. <br />
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Saturn has 30 named satellites and more continue to be discovered.<br />
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<div align="center"><b><span style="font-size: large;"><span style="color: #274e13;">Saturn Statistics</span></span></b></div><div align="center"><b><span style="font-size: large;"> </span></b><br />
<b><span style="color: #4c1130;">Mass (kg)</span></b><b><span style="color: orange;"> </span> 5.688e+26<br />
<span style="color: #4c1130;">Mass (Earth = 1)</span> 9.5181e+01<br />
<span style="color: #4c1130;">Equatorial radius (km)</span> 60,268 <br />
<span style="color: #4c1130;">Equatorial radius (Earth = 1)</span> 9.4494e+00<br />
<span style="color: #4c1130;">Mean density (gm/cm^3)</span> 0.69<br />
<span style="color: #4c1130;">Mean distance from the Sun (km)</span> 1,429,400,000 <br />
<span style="color: #4c1130;">Mean distance from the Sun (Earth = 1 )</span> 9.5388</b><span style="color: #4c1130;"><b>Rotational period (hours)</b></span><b> 10.233<br />
<span style="color: #4c1130;">Orbital period (years)</span> 29.458<br />
<span style="color: #4c1130;">Mean orbital velocity (km/sec)</span> 9.67<br />
<span style="color: #4c1130;">Orbital eccentricity </span> 0.0560<br />
<span style="color: #4c1130;">Tilt of axis (degrees) </span> 25.33<br />
<span style="color: #4c1130;">Orbital inclination (degrees)</span> 2.488<br />
<span style="color: #4c1130;">Equatorial surface gravity (m/sec^2)</span> 9.05<br />
<span style="color: #4c1130;">Equatorial escape velocity (km/sec) </span> 35.49 <br />
<span style="color: #4c1130;">Visual geometric albedo</span> 0.47<br />
<span style="color: #4c1130;">Magnitude (Vo) </span> 0.67<br />
<span style="color: #4c1130;">Mean cloud temperature</span> -125°C<br />
<span style="color: #4c1130;">Atmospheric pressure (bars) </span> 1.4</b><br />
<b><span style="font-size: large;"><span style="color: #274e13;">Atmospheric composition</span></span></b><br />
<b><span style="color: #4c1130;">Hydrogen </span> 97%<br />
<span style="color: #4c1130;">Helium</span> 3%</b> <br />
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</div></div>Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-6092218064926085931.post-16224518462270886032011-02-15T13:04:00.000-08:002011-03-15T18:29:23.219-07:00URANUS<div dir="ltr" style="text-align: left;" trbidi="on"><div class="separator" style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjsyixnLNMYSQzLz57aKAIetwBm2HA1fOsvG0OPeDruadyRqpbIkK1lZt_oxUXk11-ptSNvU08IQpGdDaSpBrLIU9eHGobIu6g0EGyIMXSRfOFcZ4JB1-s3dDmKTzj536Ift4ta79qAtPoP/s1600/URANUS.jpg"><span style="mso-no-proof: yes; text-decoration: none; text-underline: none;"> <a href="http://www.solarviews.com/eng/people.htm#herschel"><span style="font-family: "Georgia", "Times New Roman", serif;"><br />
</span></a></span></a></div><div align="justify" class="separator" style="text-align: center;"><span style="mso-no-proof: yes; text-decoration: none; text-underline: none;"><span style="font-family: "Georgia", "Times New Roman", serif;">Uranus is the seventh planet from the Sun and is the third largest in the solar system. It was discovered by </span><a href="http://www.solarviews.com/eng/people.htm#herschel"><span style="font-family: "Georgia", "Times New Roman", serif;">William Herschel</span></a><span style="font-family: "Georgia", "Times New Roman", serif;"> in 1781. It has an equatorial diameter of 51,800 kilometers (32,190 miles) and orbits the Sun once every 84.01 Earth years. It has a mean distance from the Sun of 2.87 billion kilometers (1.78 billion miles). It rotates about its axis once every 17 hours 14 minutes. Uranus has at least 22 moons. The two largest moons, </span><a href="http://www.solarviews.com/eng/titania.htm"><span style="font-family: "Georgia", "Times New Roman", serif;">Titania</span></a><span style="font-family: "Georgia", "Times New Roman", serif;"> and </span><a href="http://www.solarviews.com/eng/oberon.htm"><span style="font-family: "Georgia", "Times New Roman", serif;">Oberon</span></a><span style="font-family: "Georgia", "Times New Roman", serif;">, were discovered by </span><span style="color: orange;"><span style="font-family: "Georgia", "Times New Roman", serif;">William Herschel</span></span><span style="font-family: "Georgia", "Times New Roman", serif;"> in 1787. </span><span style="font-family: "Georgia", "Times New Roman", serif;"><br />
</span><span style="font-family: "Georgia", "Times New Roman", serif;"> </span><span style="font-family: "Georgia", "Times New Roman", serif;"> </span><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhWMsT3rHNZRrES4ixYq8ScoMhT4_8Gs-xzTyd202NVq-rjEOY6fN7_PBOYsKwYh3XlzaYRT_r7NGP3t19cViaX_Jbq3BUK2hZOvl3cfi6b7YIVbVqAnwzj-Qg3oU_PdgMnEiy0O_O6SggH/s1600/URANUS.jpg" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="240" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhWMsT3rHNZRrES4ixYq8ScoMhT4_8Gs-xzTyd202NVq-rjEOY6fN7_PBOYsKwYh3XlzaYRT_r7NGP3t19cViaX_Jbq3BUK2hZOvl3cfi6b7YIVbVqAnwzj-Qg3oU_PdgMnEiy0O_O6SggH/s320/URANUS.jpg" width="320" /></a></div><span style="font-family: "Georgia", "Times New Roman", serif;"><br />
</span><span style="font-family: "Georgia", "Times New Roman", serif;"> </span><span style="font-family: "Georgia", "Times New Roman", serif;"> The atmosphere of Uranus is composed of 83% hydrogen, 15% helium, 2% methane and small amounts of acetylene and other hydrocarbons. Methane in the upper atmosphere absorbs red light, giving Uranus its blue-green color. The atmosphere is arranged into clouds running at constant latitudes, similar to the orientation of the more vivid latitudinal bands seen on Jupiter and Saturn. Winds at mid-latitudes on Uranus blow in the direction of the planet's rotation. These winds blow at velocities of 40 to 160 meters per second (90 to 360 miles per hour). Radio science experiments found winds of about 100 meters per second blowing in the opposite direction at the equator. </span><span style="font-family: "Georgia", "Times New Roman", serif;"><br />
</span><span style="font-family: "Georgia", "Times New Roman", serif;"> </span><span style="font-family: "Georgia", "Times New Roman", serif;"> </span><span style="font-family: "Georgia", "Times New Roman", serif;"><br />
</span><span style="font-family: "Georgia", "Times New Roman", serif;"> </span><span style="font-family: "Georgia", "Times New Roman", serif;"> Uranus is distinguished by the fact that it is tipped on its side. Its unusual position is thought to be the result of a collision with a planet-sized body early in the solar system's history. </span><a href="http://www.solarviews.com/eng/voyager.htm"><span style="font-family: "Georgia", "Times New Roman", serif;">Voyager 2</span></a><span style="font-family: "Georgia", "Times New Roman", serif;"> found that one of the most striking influences of this sideways position is its effect on the tail of the magnetic field, which is itself tilted 60 degrees from the planet's axis of rotation. The </span><a href="http://www.solarviews.com/eng/terms.htm#magnetotail"><span style="font-family: "Georgia", "Times New Roman", serif;">magnetotail</span></a><span style="font-family: "Georgia", "Times New Roman", serif;"> was shown to be twisted by the planet's rotation into a long corkscrew shape behind the planet. The magnetic field source is unknown; the electrically conductive, super-pressurized ocean of water and ammonia once thought to lie between the core and the atmosphere now appears to be nonexistent. The magnetic fields of Earth and other planets are believed to arise from electrical currents produced in their molten cores. </span><span style="font-family: "Georgia", "Times New Roman", serif;"><br />
</span><span style="font-family: "Georgia", "Times New Roman", serif;"> </span><span style="font-family: "Georgia", "Times New Roman", serif;"> </span><b><span style="color: #3d85c6;"><span style="font-family: "Georgia", "Times New Roman", serif;">Uranus' Rings</span></span></b><span style="font-family: "Georgia", "Times New Roman", serif;"><br />
</span><span style="font-family: "Georgia", "Times New Roman", serif;"> </span><span style="font-family: "Georgia", "Times New Roman", serif;"> </span><span style="font-family: "Georgia", "Times New Roman", serif;"><br />
</span><span style="font-family: "Georgia", "Times New Roman", serif;"> </span><span style="font-family: "Georgia", "Times New Roman", serif;"> In 1977, the first nine rings of Uranus were discovered. During the Voyager encounters, these rings were photographed and measured, as were two other new rings and ringlets. Uranus' rings are distinctly different from those at </span><a href="http://oursolarsysteminfo.blogspot.com/2011/02/jupiter.html"><span style="font-family: "Georgia", "Times New Roman", serif;">Jupiter</span></a><span style="font-family: "Georgia", "Times New Roman", serif;"> and </span><a href="http://oursolarsysteminfo.blogspot.com/2011/02/saturn.html"><span style="font-family: "Georgia", "Times New Roman", serif;">Saturn</span></a><span style="font-family: "Georgia", "Times New Roman", serif;">. The outermost epsilon ring is composed mostly of ice boulders several feet across. A very tenuous distribution of fine dust also seems to be spread throughout the ring system. </span><span style="font-family: "Georgia", "Times New Roman", serif;"><br />
</span><span style="font-family: "Georgia", "Times New Roman", serif;"> </span><span style="font-family: "Georgia", "Times New Roman", serif;"> </span><span style="font-family: "Georgia", "Times New Roman", serif;"><br />
</span><span style="font-family: "Georgia", "Times New Roman", serif;"> </span><span style="font-family: "Georgia", "Times New Roman", serif;"> There may be a large number of narrow rings, or possibly incomplete rings or ring arcs, as small as 50 meters (160 feet) in width. The individual ring particles were found to be of low reflectivity. At least one ring, the epsilon, was found to be gray in color. The moons Cordelia and Ophelia act as </span><a href="http://www.solarviews.com/eng/terms.htm#shepherd"><span style="font-family: "Georgia", "Times New Roman", serif;">shepherd satellites</span></a><span style="font-family: "Georgia", "Times New Roman", serif;"> for the epsilon ring.</span><span style="font-family: "Georgia", "Times New Roman", serif;"><br />
</span><span style="font-family: "Georgia", "Times New Roman", serif;"> </span><div align="center" class="MsoNormal"><span style="font-family: "Georgia", "Times New Roman", serif;"><br />
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<b><span style="font-size: large;"><span style="color: #274e13;">Uranus Statistics</span></span><br />
<span style="color: blue;">Discovered by William Herschel</span><br />
<span style="color: #b45f06;">Date of discovery 1781</span><br />
<span style="color: #4c1130;">Mass (kg) </span> 8.686e+25<br />
<span style="color: #4c1130;">Mass (Earth = 1)</span> 1.4535e+01<br />
<span style="color: #4c1130;">Equatorial radius (km)</span> 25,559<br />
<span style="color: #4c1130;">Equatorial radius (Earth = 1)</span> 4.0074<br />
<span style="color: #4c1130;">Mean density (gm/cm^3)</span> 1.29<br />
<span style="color: #4c1130;">Mean distance from the Sun (km)</span> 2,870,990,000<br />
<span style="color: #4c1130;">Mean distance from the Sun (Earth = 1)</span> 19.1914<br />
<span style="color: #4c1130;">Rotational period (hours)</span> -17.9<br />
<span style="color: #4c1130;">Orbital period (years)</span> 84.01<br />
<span style="color: #4c1130;">Mean orbital velocity (km/sec)</span> 6.81<br />
<span style="color: #4c1130;">Orbital eccentricity</span> 0.0461<br />
<span style="color: #4c1130;">Tilt of axis (degrees)</span> 97.86<br />
<span style="color: #4c1130;"><span style="background-color: white;">Orbital inclination (degrees)</span></span> 0.774<br />
<span style="background-color: #4c1130;"><span style="background-color: white;"><span style="color: #4c1130;">Equatorial surface gravity (m/sec^2)</span> </span></span> 7.77<br />
<span style="color: #4c1130;">Equatorial escape velocity (km/sec)</span> 21.30<br />
<span style="color: #4c1130;">Visual geometric albedo</span> 0.51<br />
<span style="color: #4c1130;">Magnitude (Vo)</span> 5.52 <br />
<span style="color: #4c1130;">Mean cloud temperature </span> -193°C<br />
<span style="color: #4c1130;">Atmospheric pressure (bars)</span> 1.2<br />
<span style="font-size: large;"><span style="color: #274e13;">Atmospheric composition</span></span> <br />
<span style="color: #4c1130;">Hydrogen</span></b><b> 83%</b><b><br />
<span style="color: #4c1130;">Helium</span></b><b> 15%</b><b><br />
<span style="color: #4c1130;">Methan</span>e </b><b>2%</b><b> <br />
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</div>Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-6092218064926085931.post-89218474278004841842011-02-15T12:59:00.000-08:002011-03-15T18:30:32.638-07:00NEPTUNE<div dir="ltr" style="text-align: left;" trbidi="on"><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhs-j5YiYmng6aYzpau4DLAM0oTz4DIsrttOudaj-3QWL3Qr2X5tgvYdGFTcl-iA2HhHcFLlcjTwXjuV_4amsV6L62HOpaes_L7R_KhIT5BmxqfPpAmaixSt03v-uKS7AXxywIczNX1I-_H/s1600/neptune.jpg" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;">l<img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhs-j5YiYmng6aYzpau4DLAM0oTz4DIsrttOudaj-3QWL3Qr2X5tgvYdGFTcl-iA2HhHcFLlcjTwXjuV_4amsV6L62HOpaes_L7R_KhIT5BmxqfPpAmaixSt03v-uKS7AXxywIczNX1I-_H/s1600/neptune.jpg" /></a></div><br />
<span style="font-family: "Georgia", "Times New Roman", serif;">Neptune is the outermost planet of the gas giants. It has an equatorial diameter of 49,500 kilometers (30,760 miles). If Neptune were hollow, it could contain nearly 60 Earths. Neptune orbits the Sun every 165 years. It has eight moons, six of which were found by </span><a href="http://www.solarviews.com/eng/voyager.htm"><span style="font-family: "Georgia", "Times New Roman", serif;">Voyager</span></a><span style="font-family: "Georgia", "Times New Roman", serif;">. A day on Neptune is 16 hours and 6.7 minutes. Neptune was discovered on September 23, 1846 by </span><a href="http://www.solarviews.com/eng/people.htm#galle"><span style="font-family: "Georgia", "Times New Roman", serif;">Johann Gottfried Galle</span></a><span style="font-family: "Georgia", "Times New Roman", serif;"> Galle, of the Berlin Observatory, and Louis d'Arrest, an astronomy student, through mathematical predictions made by Urbain Jean Joseph Le Verrier. </span><br />
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<span style="font-family: "Georgia", "Times New Roman", serif;">The first two thirds of Neptune is composed of a mixture of molten rock, water, liquid ammonia and methane. The outer third is a mixture of heated gases comprised of hydrogen, helium, water and methane. Methane gives Neptune its blue cloud color. </span><br />
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<span style="font-family: "Georgia", "Times New Roman", serif;">Neptune is a dynamic planet with several large, dark spots reminiscent of </span><a href="http://oursolarsysteminfo.blogspot.com/2011/02/jupiter.html"><span style="font-family: "Georgia", "Times New Roman", serif;">Jupiter's</span></a><span style="font-family: "Georgia", "Times New Roman", serif;"> hurricane-like storms. The largest spot, known as the </span><a href="http://www.solarviews.com/eng/neptune.htm#darkspot"><span style="font-family: "Georgia", "Times New Roman", serif;">Great Dark Spot</span></a><span style="font-family: "Georgia", "Times New Roman", serif;">, is about the size of the earth and is similar to the </span><a href="http://www.solarviews.com/eng/jupiter.htm#redspot"><span style="font-family: "Georgia", "Times New Roman", serif;">Great Red Spot</span></a><span style="font-family: "Georgia", "Times New Roman", serif;"> on Jupiter. Voyager revealed a small, irregularly shaped, eastward-moving cloud scooting around Neptune every 16 hours or so. This scooter as it has been dubbed could be a plume rising above a deeper cloud deck. </span><br />
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<span style="font-family: "Georgia", "Times New Roman", serif;">Long bright clouds, similar to cirrus clouds on Earth, were seen high in Neptune's atmosphere. At low northern latitudes, Voyager captured images of cloud streaks casting their shadows on cloud decks below. </span><br />
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<span style="font-family: "Georgia", "Times New Roman", serif;">The strongest winds on any planet were measured on Neptune. Most of the winds there blow westward, opposite to the rotation of the planet. Near the Great Dark Spot, winds blow up to 2,000 kilometers (1,200 miles) an hour. </span><br />
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<span style="font-family: "Georgia", "Times New Roman", serif;">Neptune has a set of four rings which are narrow and very faint. The rings are made up of dust particles thought to have been made by tiny meteorites smashing into Neptune's moons. From ground based telescopes the rings appear to be arcs but from Voyager 2 the arcs turned out to be bright spots or clumps in the ring system. The exact cause of the bright clumps is unknown. </span><br />
<span style="font-family: "Georgia", "Times New Roman", serif;"><br />
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<span style="font-family: "Georgia", "Times New Roman", serif;">The magnetic field of Neptune, like that of </span><a href="http://oursolarsysteminfo.blogspot.com/2011/02/uranus-is-seventh-planet-from-sun-and.html"><span style="font-family: "Georgia", "Times New Roman", serif;">Uranus</span></a><span style="font-family: "Georgia", "Times New Roman", serif;">, is highly tilted at 47 degrees from the rotation axis and offset at least 0.55 radii (about 13,500 kilometers or 8,500 miles) from the physical center. Comparing the magnetic fields of the two planets, scientists think the extreme orientation may be characteristic of flows in the interior of the planet and not the result of that planet's sideways orientation or of any possible field reversals at either planet.</span><br />
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<div align="center"><b><span style="font-size: large;">Neptune Statistics</span></b><span style="font-size: large;"><b> </b></span></div><div align="center"><span style="font-size: small;"><b><span style="color: blue;">Discovered by Johann Gotfried Galle</span></b><b><br />
</b><b> <span style="color: #b45f06;">Date of discovery September 23, 1846</span></b><b><br />
</b><b> <span style="color: #4c1130;">Mass (kg)</span> 1.024e+26</b><b><br />
</b><b> <span style="color: #4c1130;">Mass (Earth = 1)</span> 1.7135e+01</b><b><br />
</b><b> <span style="color: #4c1130;">Equatorial radius (km)</span> 24,746</b><b><br />
</b><b> <span style="color: #4c1130;">Equatorial radius (Earth = 1)</span> 3.8799e+00</b><b><br />
</b><b> <span style="color: #4c1130;">Mean density (gm/cm^3)</span> 1.64</b><b><br />
</b><b> <span style="color: #4c1130;">Mean distance from the Sun (km)</span> 4,504,300,000</b><b><br />
</b><b> <span style="color: #4c1130;">Mean distance from the Sun (Earth = 1)</span> 30.0611</b><b><br />
</b><b> <span style="color: #4c1130;">Rotational period (hours)</span> 16.11 </b><b><br />
</b><b> <span style="color: #4c1130;">Orbital period (years)</span> 164.79</b><b><br />
</b><b> <span style="color: #4c1130;">Mean orbital velocity (km/sec) </span> 5.45</b><b><br />
</b><b> <span style="color: #4c1130;">Orbital eccentricity</span> 0.0097</b><b><br />
</b><b> <span style="color: #4c1130;">Tilt of axis (degrees)</span> 29.56</b><b><br />
</b><b> <span style="color: #4c1130;">Orbital inclination (degrees)</span> 1.774</b><b><br />
</b><b> <span style="color: #4c1130;">Equatorial surface gravity (m/sec^2)</span> 11.0</b><b><br />
</b><b> <span style="color: #4c1130;">Equatorial escape velocity (km/sec)</span> 23.50</b><b><br />
</b><b> <span style="color: #4c1130;">Visual geometric albedo</span> 0.41</b><b><br />
</b><b> <span style="color: #4c1130;">Magnitude (Vo) </span> 7.84</b><b><br />
</b><b> <span style="color: #4c1130;">Mean cloud temperature</span> -193 to -153°C</b><b><br />
</b><b> <span style="color: #4c1130;">Atmospheric pressure (bars)</span> 1-3</b></span><br />
<b><span style="font-size: large;"><span style="color: #274e13;">Atmospheric composition </span></span></b></div><div align="center"><span style="font-size: small;"><b><span style="color: #4c1130;">Hydrogen</span></b></span><span style="font-size: small;"><b> 85%</b></span><span style="font-size: small;"><b><br />
</b><b> <span style="color: #4c1130;">Helium</span></b></span><span style="font-size: small;"><b> 13%</b></span><span style="font-size: small;"><b><br />
</b><b> <span style="color: #4c1130;">Methane</span> </b></span><span style="font-size: small;"><b>2%</b></span><span style="font-size: small;"><b> </b><br />
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</span></b></div></div>Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-6092218064926085931.post-31272852424910336492011-02-15T12:25:00.000-08:002011-03-15T18:32:11.189-07:00PLUTO<div dir="ltr" style="text-align: left;" trbidi="on"><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjX7PV_1I0y-3KnguSXghdOH2xoehTip9j0PjEEOABSj5DhOI9oNj-t61U15G0yeSv5eIfBewX3gSarr0J5EzqCUDO43C6C1NJJZhvwvySm-P58je9GpIRDzgihMfKrecVyijMbw-JaDlnJ/s1600/2758127977_42149bec97.jpg" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjX7PV_1I0y-3KnguSXghdOH2xoehTip9j0PjEEOABSj5DhOI9oNj-t61U15G0yeSv5eIfBewX3gSarr0J5EzqCUDO43C6C1NJJZhvwvySm-P58je9GpIRDzgihMfKrecVyijMbw-JaDlnJ/s320/2758127977_42149bec97.jpg" width="213" /></a></div><br />
<span style="font-family: "Georgia", "Times New Roman", serif;">Although Pluto was discovered in 1930, limited information on the distant object delayed a realistic understanding of its characteristics. Pluto is the second largest known dwarf planet and tenth largest orbiting the Sun. From its time of discovery in 1930 to 2006 it was considered to be the ninth planet in the solar system, but because additional objects have been discovered including Eris which is 27% more massive, the IAU reclassified Pluto and the other objects as dwarf planets. The New Horizons spacecraft was launched on January 16, 2006 and will make its closest approach to Pluto on July 14, 2015. This mission will provide an increased amount of information about this peculiar dwarf planet. The uniqueness of Pluto's orbit, rotational relationship with its satellite, spin axis, and light variations all give it a certain appeal. </span><br />
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<span style="font-family: "Georgia", "Times New Roman", serif;">Pluto is usually farther from the </span><a href="http://oursolarsysteminfo.blogspot.com/2011/03/sun.html"><span style="font-family: "Georgia", "Times New Roman", serif;">Sun</span></a><span style="font-family: "Georgia", "Times New Roman", serif;"> than any of the eight planets; however, due to the eccentricity of its orbit, it is closer than </span><a href="http://oursolarsysteminfo.blogspot.com/2011/02/neptune.html"><span style="font-family: "Georgia", "Times New Roman", serif;">Neptune</span></a><span style="font-family: "Georgia", "Times New Roman", serif;"> for 20 years out of its 249 year orbit. Pluto crossed Neptune's orbit January 21, 1979, made its closest approach September 5, 1989, and remained within the orbit of Neptune until February 11, 1999. This will not occur again until September 2226. </span><br />
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<span style="font-family: "Georgia", "Times New Roman", serif;">As Pluto approaches </span><a href="http://www.solarviews.com/eng/terms.htm#perihelion"><span style="font-family: "Georgia", "Times New Roman", serif;">perihelion</span></a><span style="font-family: "Georgia", "Times New Roman", serif;"> it reaches its maximum distance from the </span><a href="http://www.solarviews.com/eng/terms.htm#ecliptic"><span style="font-family: "Georgia", "Times New Roman", serif;">ecliptic</span></a><span style="font-family: "Georgia", "Times New Roman", serif;"> due to its 17-degree inclination. Thus, it is far above or below the plane of Neptune's orbit. Under these conditions, Pluto and Neptune will not collide and do not approach closer than 18 A.U. to one another. </span><br />
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<span style="font-family: "Georgia", "Times New Roman", serif;">Pluto's rotation period is 6.387 days, the same as its satellite Charon. Although it is common for a satellite to travel in a </span><a href="http://www.solarviews.com/eng/terms.htm#syncrot"><span style="font-family: "Georgia", "Times New Roman", serif;">synchronous orbit</span></a><span style="font-family: "Georgia", "Times New Roman", serif;"> with its planet, Pluto rotates synchronously with the orbit of its satellite. Thus being tidally locked, Pluto and Charon continuously face each other as they travel through space. </span><br />
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<span style="font-family: "Georgia", "Times New Roman", serif;">Unlike most planets, but similar to </span><a href="http://oursolarsysteminfo.blogspot.com/2011/02/uranus-is-seventh-planet-from-sun-and.html"><span style="font-family: "Georgia", "Times New Roman", serif;">Uranus</span></a><span style="font-family: "Georgia", "Times New Roman", serif;">, Pluto rotates with its poles almost in its orbital plane. Pluto's rotational axis is tipped 122 degrees. When Pluto was first discovered, its relatively bright south polar region was the view seen from the Earth. Pluto appeared to grow dim as our viewpoint gradually shifted from nearly pole-on in 1954 to nearly equator-on in 1973. Pluto's equator is now the view seen from </span><a href="http://oursolarsysteminfo.blogspot.com/2011/02/earth.html"><span style="font-family: "Georgia", "Times New Roman", serif;">Earth</span></a><span style="font-family: "Georgia", "Times New Roman", serif;">. </span><br />
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<span style="font-family: "Georgia", "Times New Roman", serif;">During the period from 1985 through 1990, Earth was aligned with the orbit of Charon around Pluto such that an </span><a href="http://www.solarviews.com/eng/terms.htm#eclipse"><span style="font-family: "Georgia", "Times New Roman", serif;">eclipse</span></a><span style="font-family: "Georgia", "Times New Roman", serif;"> could be observed every Pluto day. This provided opportunity to collect significant data which led to </span><a href="http://www.solarviews.com/eng/terms.htm#albedo"><span style="font-family: "Georgia", "Times New Roman", serif;">albedo</span></a><span style="font-family: "Georgia", "Times New Roman", serif;"> maps defining surface reflectivity, and to the first accurate determination of the sizes of Pluto and Charon, including all the numbers that could be calculated therefrom. </span><br />
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<span style="font-family: "Georgia", "Times New Roman", serif;">The first eclipses (mutual events) began blocking the north polar region. Later eclipses blocked the equatorial region, and final eclipses blocked Pluto's south polar region. By carefully measuring the brightness over time, it was possible to determine surface features. It was found that Pluto has a highly reflective south polar cap, a dimmer north polar cap, and both bright and dark features in the equatorial region. Pluto's geometric albedo is 0.49 to 0.66, which is much brighter than Charon. Charon's albedo ranges from 0.36 to 0.39. </span><br />
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<span style="font-family: "Georgia", "Times New Roman", serif;">The eclipses lasted as much as four hours and by carefully timing their beginning and ending, measurements for their diameters were taken. The diameters can also be measured directly to within about 1 percent by more recent images provided by the Hubble Space Telescope. These images resolve the objects to clearly show two separate disks. The improved optics allow us to measure Pluto's diameter as 2,274 kilometers (1413 miles) and Charon's diameter as 1,172 kilometers (728 miles), just over half the size of Pluto. Their average separation is 19,640 km (12,200 miles). That's roughly eight Pluto diameters. </span><br />
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<span style="font-family: "Georgia", "Times New Roman", serif;">Average separation and orbital period are used to calculate Pluto and Charon's masses. Pluto's mass is about 6.4 x 10-9 solar masses. This is close to 7 (was 12 x's) times the mass of Charon and approximately 0.0021 Earth mass, or a fifth of our moon. </span><br />
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<span style="font-family: "Georgia", "Times New Roman", serif;">Pluto's average </span><a href="http://www.solarviews.com/eng/terms.htm#density"><span style="font-family: "Georgia", "Times New Roman", serif;">density</span></a><span style="font-family: "Georgia", "Times New Roman", serif;"> lies between 1.8 and 2.1 grams per cubic centimeter. It is concluded that Pluto is 50% to 75% rock mixed with ices. Charon's density is 1.2 to 1.3 g/cm3, indicating it contains little rock. The differences in density tell us that Pluto and Charon formed independently, although Charon's numbers derived from HST data are still being challenged by ground based observations. Pluto and Charon's origin remains in the realm of theory. </span><br />
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<span style="font-family: "Georgia", "Times New Roman", serif;">Pluto's icy surface is 98% nitrogen (N2). Methane (CH4) and traces of carbon monoxide (CO) are also present. The solid methane indicates that Pluto is colder than 70 Kelvin. Pluto's temperature varies widely during the course of its orbit since Pluto can be as close to the sun as 30 AU and as far away as 50 AU. There is a thin atmosphere that freezes and falls to the surface as the planet moves away from the Sun. The atmospheric pressure deduced for Pluto's surface is 1/100,000 that of Earth's surface pressure. </span><br />
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<span style="font-family: "Georgia", "Times New Roman", serif;">Pluto was officially labeled the ninth planet by the International Astronomical Union in 1930 and named for the Roman god of the underworld. It was the first and only planet to be discovered by an American, Clyde W. Tombaugh. It has since been reclassified as a Dwarf Planet along with </span><a href="http://www.solarviews.com/eng/eris.htm"><span style="font-family: "Georgia", "Times New Roman", serif;">Eris</span></a><span style="font-family: "Georgia", "Times New Roman", serif;"> and </span><a href="http://www.solarviews.com/eng/ceres.htm"><span style="font-family: "Georgia", "Times New Roman", serif;">Ceres</span></a><span style="font-family: "Georgia", "Times New Roman", serif;">. </span><br />
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<span style="font-family: "Georgia", "Times New Roman", serif;">The path toward its discovery is credited to Percival Lowell who founded the Lowell Observatory in Flagstaff, Arizona and funded three separate searches for "Planet X." Lowell made numerous unsuccessful calculations to find it, believing it could be detected from the effect it would have on Neptune's orbit. Dr. Vesto Slipher, the observatory director, hired Clyde Tombaugh for the third search and Clyde took sets of photographs of the plane of the solar system (ecliptic) one to two weeks apart and looked for anything that shifted against the backdrop of stars. This systematic approach was successful and Pluto was discovered by this young (born 4 Feb 1906) 24 year old Kansas lab assistant on February 18, 1930. Pluto is actually too small to be the "Planet X" Percival Lowell had hoped to find. Pluto's was a serendipitous discovery.</span><br />
<div align="center"><b><span style="font-size: large;"><span style="color: #274e13;">Pluto Statistics</span></span></b></div><div align="center"><span style="color: blue;"><b>Discovered by Clyde W. Tombaugh</b></span><br />
<span style="color: #b45f06;"><b>Date of discovery February 18, 1930</b></span><br />
<span style="color: #4c1130;"><b>Mass (kg)</b></span><b> 1.27e+22</b><br />
<span style="color: #4c1130;"><b>Mass (Earth = 1)</b></span><b> 2.125e-03</b><br />
<span style="color: #4c1130;"><b>Equatorial radius (km)</b></span><b> 1,137</b><br />
<b><span style="color: #4c1130;">Equatorial radius (Earth = 1)</span> 0.1783</b><br />
<b><span style="color: #4c1130;">Mean density (gm/cm^3)</span> 2.05</b><br />
<b><span style="color: #4c1130;">Mean distance from the Sun (km)</span> 5,913,520,000</b><br />
<b><span style="color: #4c1130;">Mean distance from the Sun (Earth = 1)</span> 39.5294</b><br />
<b><span style="color: #4c1130;">Rotational period (days)</span> -6.3872</b><br />
<b><span style="color: #4c1130;">Orbital period (years)</span> 248.54</b><br />
<b><span style="color: #4c1130;">Mean orbital velocity (km/sec)</span> 4.74</b><br />
<b><span style="color: #4c1130;">Orbital eccentricity</span> 0.2482</b><br />
<b><span style="color: #4c1130;">Tilt of axis (degrees)</span> 122.52</b><br />
<b><span style="color: #4c1130;">Orbital inclination (degrees)</span> 17.148</b><br />
<b><span style="color: #4c1130;">Equatorial surface gravity (m/sec^2)</span> 0.4</b><br />
<b><span style="color: #4c1130;">Equatorial escape velocity (km/sec)</span> 1.22</b><br />
<b><span style="color: #4c1130;">Visual geometric albedo 0.3</span></b><br />
<b><span style="color: #4c1130;">Magnitude (Vo) </span> 15.12 </b><br />
<span style="font-size: large;"><span style="color: #274e13;"><b>Atmospheric composition</b></span></span><b> </b><br />
<b><span style="color: #4c1130;">Methane</span> </b><b>0.3</b><br />
<b><span style="color: #4c1130;">Nitrogen </span> </b></div></div>Unknownnoreply@blogger.com0