Solar System Planets Essay Example For Students

Solar System Planets Essay The earth is only one small planet in an extremely large system of planets,satellites, asteroids, meteors and comets that revolve around the sun. Thissystem is referred to as the solar system. A planet is defined as a celestialbody that revolves around a central star and does not shine by its own light (Grolier,1992). The only planetary system known to our civilization isour solar system. It is made up of nine planets that differ greatly size andphysical characteristics. The nine major planets in our solar system areMercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto. Thereare also many other minor planets which are also in our solar system, but theyare unimportant compared to the nine major planets. Following are descriptionsof the differences that each of the nine planets have. The first planet to bediscussed is Mercury. Mercury is the planet that is closest to the sun at anaverage distance of about 58 million km, or about 36 million miles. It takes58.7 days for Mercury to rotate. The planet rotates one and one half timesduring each revolution. Mercury has a density and composition close to that ofEarth and, like Earth has a magnetic field. This magnetic field is produced fromthe planets outer core, which is said to be liquid iron. This liquid irongenerates a magnetic field with its movement. The atmosphere is extremely thinand contains sodium and potassium. The photographs that have been taken ofMercurys surface show the planet having craters and steep cliffs. Thetemperatures on Mercury reach amazingly high levels of about 430? C, which isabout 810? F on the side facing the sun and about -180? C, or about 290? F onthe side facing away from the sun. It is speculated that these hightemperatures, resulting from the planets proximity to the sun made itimpossible for the gases present to become part of the planetary formation orfor Mercury to have any type of atmosphere. Venus is the second closest planetto the sun and is said to most closely resemble Earth in size, density, anddistance from the sun. Venus is known as the sister planet to the Earth. Onedifferences is that Venus is shrouded in thick clouds that completely hide thesurface of the planet. The surface temperature is also much warmer than that ofEarth. Venus completes one revolution around the sun in 224.7 days. This makesthe a day on Venus equal to 117 earth days. It is thought that this slowrotation may be the reason why Venus has no magnetic field. The atmosphere ofVenus made up of 98% carbon dioxide and 2% Nitrogen. This atmosphere also hasthe presence of helium, neon, and argon. The surface of Venus is quite a bitlike that of the Earth. Cloud particles on Venus are mostly concentratedsulfuric acid. Water and water vapor are very uncommon on Venus. Many scientistshold the opinion that Venus, being close to the sun, was subjected to a kind ofextreme greenhouse effect. This effect caused any oceans to evaporate into theatmosphere. Another viewpoint that is h eld is that Venus had very little waterto begin with. The surface has volcanoes and smooth plains. Much of the volcanicactivity on Venus takes the form of Basaltic eruptions that inundate largeareas, much as the mare volcanism flooded the impacted basins on the near sideof the moon. Because of the distances of the orbits of Venus and Earth from thesun, Venus can never be seen for than three hours before sunrise or three hoursafter sunset. When Venus is viewed through a telescope, it shows phases like themoon. Venus rotates very slowly on its axis, in a direction that is opposite tothat of Earth. Cloud particles on Venus are mostly concentrated sulfuric acid. Water and water vapor are very uncommon on Venus. Many scientists hold theopinion that Venus, being close to the sun, was subjected to a kind of extremegreenhouse effect. This effect caused any oceans to evaporate into theatmosphere. Another viewpoint that is held is that Venus had very little waterto begin with. Higher-level winds circle the entire planet at 360 km/hr., or 225mph. However, even with these high velocity winds, near the planets surfacemore than half of Venuss tremendously dense atmosphere is practically still. From the surface up to 10 km, or 6 mi. altitude, wind speeds are only about 3 to18 km/hr, or about 2 to 11 mph. In the upper atmosphere, the night side of Venusis extremely cold. Day-side temperatures are 40? C, or 104? F but night-sidetemperatures are -170? C, or 274? F. Scientists theorize that strong windsblow from the day side toward the near vacuum that is caused by the lowtemperatures on the night-side. Venus has huge active volcanoes, largesolidified lava flows, and a vast number of meteorite craters. The compositionof Venuss dense atmosphere apparently prevents smaller meteorites from crashinginto the surface of the planet. A great deal of tectonic activity has takenplace on Venus, at least in the past. Venus is the second closest planet to thesun and is said to . . . most closely resemble Earth in size, density,and distance from the sun . Venus is often referred to by scientists asthe sister planet to the Earth. It is called this because it closely resemblesthe Earths mass, density and diameter. The only thing different is that Venus is shrouded in thick clouds that completely hide the surface of theplanet (Grolier, 1992). The surface temperature is also much warmer thanthat of Earth. Venus completes one revolution around the sun in 224.7 days. Thismakes the Venusian day equal to 117 earth days. It is thought that this slowrotation may be the reason why Venus has no magnetic field. Mars is the fourthfurthest away from the sun and is recognized by its reddish color. Mars is alsovery much like the Earth. More than any other planet in the solar system,Mars has characteristics that make it an Earth-like world (Grolier, 1992). Analysis of Sexual Harassment EssayOne of Saturns rings is dense enough to block sunlight. The atmosphere ofSaturn is predominantly made up of a clear hydrogen-helium atmosphere. Methane,phosphine, ethane, and acetylene are also identifiable in smaller amounts. Saturn orbits the sun with a period of 29.4577 tropical years. It is 1.427billion Km away from the sun and is therefore an extremely cold planet. However,the gravitational situation of Saturn causes it to emit three times as much heatas it receives from the sun. Uranus is the seventh planet from the sun, and islocated between Saturn and Neptune. Uranus was discovered in 1781 by the Britishastronomer Sir William Herschel and was originally named Georgium Sidus, or theStar of George, in honor of King George III of Great Britain. The name Uranus,proposed by German astronomer Johann Elert Bode, was in use by the late 19thcentury. Uranus has a diameter of 51,120 km, and its average distance from thesun is 2.87 billion km. It has a mass greater than Earths. Uranus orbits thesun once every 84 years and rotates on its axis in 17 hours 15 minutes. Itsatmosphere is mostly hydrogen and helium, with a trace of methane. Through atelescope it appears as a blue-green disk with a faint green rim. Ni ne ringsorbit Uranus, which also has 15 satellites revolving around its equator. Thelargest moons are named Oberon, Titania, Umbriel, Ariel, and Miranda. Eventhough there have been estimates made, the main problem scientists have withUranus is that this planet does not have visible surface features, which meansthat it is difficult to measure the rotation period of Uranus because they arenot sure which part of the planet they are viewing. Uranus has an equatorialdiameter of 51,000 Km which is almost four times as much as Earth. Theatmosphere is mostly methane gas and therefore the planet has a red tint or ablueish green color. Uranus also has rings but unlike Saturn these rings havealmost no small particles. Scientists are not as concerned with this planet, andhave not determined that there are any significant scientific findings to bemade on its surface. Neptune is the last of the gaseous planets in our solarsystem. Neptune is the fourth largest planet in the solar system, and eight h inits distance from the sun. Its atmosphere is much like Uranuss because itcontains predominantly helium and hydrogen. It also contains methane which givesit its blue color. Neptune has a diameter of 49,500 Km and a mass 17 timesgreater than that of the Earth. Neptune is about 4.5 billion km from the sun. Itis about 49,400 km in diameter, almost 4 times as wide as Earth. Neptunesdeep atmosphere surrounds a liquid surface and a solid core. Neptune rotates onits axis every 16 hours and orbits the sun in 164.79 Earth years. Because of thelack of light on the planet It cannot be seen with the naked eye, but ratherrequires the usage of a telescope. Neptune has five thin rings and eight knownsatellites. The largest is of the satellites is Triton, with a diameter of 2705km, which is only slightly smaller than Earths moon. Triton has a nitrogenatmosphere, with some methane, and an active planetary surface with geysers. Thesatellite Nereid has a diameter of about 320km. Neptune also has ri ngs like itsother gaseous partners, but they are very faint. Not a great deal is known aboutNeptune. It is widely studied by scientists and that makes it an importantplanet. Pluto, the last planet to be discussed, is the smallest of the planetsand the farthest from the son. This planet, like Neptune, is not extremelyvisibly, and cannot be studied extensively. Pluto is made of much rockiermaterial than are the other planets of the outer solar system. Many astronomersthink Pluto may be a former satellite of Neptune, which was possibly knockedinto a separate orbit during the early days of the solar system. is very hard tosee therefore not a lot is known about its physical characteristics. Scientistsdo know that it has a thin methane atmosphere. Little is known about this planetbecause it is so far away from the Earth and the sun. Scientists are alwayslearning new things and more data will arise in the future. As one can see theplanets of most importance are the ones closest to the sun and Earth. Little isknown about the far off planets therefore it is hard to give them fullrecognition. Much is known about Mercury, Venus, Earth, Mars, Jupiter andSaturn. The other three planets are not as well known as these six are. Whethermore planetary systems exist doesnt really matter. There are still plenty ofthings we dont understand about our own solar system. Scientists will havetheir work cut out for them in the future. Each and every planet has distinctdifferences and that helps show us how truly great God is. The planets willnever fully be understood and will always be a great topic of discussion. BibliographyCattermole, P. (1995). Earth and Other Planets. New York: Oxford UniversityPress. Grolier Electronic Publishing, Inc. (1992).