The Planets and the Solar System Planets 2″ A planet is a celestial body that revolves around acentral star and does not shine by its own light ” (Grolier,1992). The only planetary system that is known to man is oursolar system. It is made up of nine planets which range in sizeand make-up. The nine major planets in our solar system areMercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune andPluto.
There are also many other minor planets which are also inour solar system, but they are unimportant compared to the ninemajor planets. In this paper I will discuss the planets and howMercury which is the planet that is closest to the sun isthe first planet I will discuss. Mercury is the smallest of theinner planets. It is speculated that the heat from the sun madeit impossible for the gases present to become part of theplanetary formation. The surface of Mercury is extremely hot.
It is approximately 470 degrees celsius on the surface and isthought to be even hotter at the two ” hot spots.” These ” hotspots ” are on opposite ends of the equator. It is the heat ofthe surface that makes it impossible for Mercury to have any typeMercury orbits the sun once every 88 days and has a truerotation period of 58.6 days. ” It is the closest planet to thesun and therefore orbits faster than any other planet “(Thompson/Turk, 542, 1993).
It is said that Mercury rotatesthree times for every two trips around the sun, so that during Planets 3every alternate perihelon passage the same face points directlyat the sun. ” Geologically, the most remarkable features ofMercury are compressional cliffs or faults, just the sort ofwrinkles that might form in the crust if the interior of theplanet shrank slightly ” (Morrison, 74, 1993). It is speculatedthat it was the solidification of Mercury’s metallic core thatcaused this global shrinkage. Mercury is also ” .
. . enrichedin metal or depleted of rock ” (Morrison, 74, 1993). It is alsobelieved that some of the inner core of Mercury is still in aScientists also believe that Mercury’s surface is made partiallyof silicate rock. The best way to describe Mercury is, ” . . .
small, heavily cratered and airless ” (Morrison, 71, 1993).Venus is the second closest planet to the sun and is said to ” . . . most closely resemble Earth in size, density, anddistance from the sun ” (Thompson/Turk, 542, 1993). Venus isknown to most scientists as the sister planet to the Earth.
Itis called this because it closely resembles the Earth’s mass,density and diameter. The only thing different is that Venus “is shrouded in thick clouds that completely hide the surface ofthe planet ” (Grolier, 1992). The surface temperature is alsoVenus completes one revolution around the sun in 224.7 days. This makes the Venusian day equal to 117 earth days.
It isthought that this slow rotation may be the reason why Venus has Planets 4The atmosphere of Venus made up of 98% carbon dioxide and 2% Nitrogen. This atmosphere also has the presence of helium,neon and argon. This is yet another thing which makes VenusThe surface of Venus is quite a bit like that of the Earth. The surface has volcanoes and smooth plains. ” Much of thevolcanic activity on Venus takes the form of Basaltic eruptionsthat inundate large ares, much as the mare volcanism flooded theimpacted basins on the near side of the moon ” (Morrison, 93,1993). One thing that differs from Earth is that there is nowater liquid on the Venusian surface.
Some of the scientific data that follows was taken out ofCattermole’s book. The mean distance from the sun is 108.20 Km. The equatorial diameter is 12,012 Km and the equatorial rotationis 243 days. Finally the mass of Venus is 4.
87*10^24(Cattermole, 63, 1993). Venus, although different than Earth, isMars is the fourth furthest away from the sun and isrecognized by its reddish color. Mars is also very much like theEarth. ” More than any other planet in the solar system, Marshas characteristics that make it an Earth-like world “(Grolier,One thing that is very similar to Earth is the rotationperiod. Mars rotation period is only thirty seven minutes longerthan the Earth’s. This would explain why Mars has significantseasonal changes just as Earth does. It is believed that the Planets 5difference between winter and summer on Mars is even greater thanMars is extremely hard to understand due to the effect ofblurring that is caused by the two atmospheres of Mars. Scientists do know, however, that Mars is relatively small andthat changes take place in the surface features when the seasonschange.
It is also known that dust storms are prevalent andleaves the surface of Mars covered by a red haze.Mars has a very thin atmosphere which is composed of carbondioxide, nitrogen, argon, water vapor and oxygen. Mars also hasno magnetic field. ” Because the atmosphere of mars is so thin,wind velocities up to several hundred Km per hour are required toraise the dust particles during a dust storm, and these fast-moving particles erode structures with a sand-blasting effect “(Grolier, 1992). Therefore, the surface is basically plain-likeand covered with large craters. There are also some areas wherethe rock is ” jumbled.” The poles of Mars are iced over and thetemperature is about 160 – 170 degrees K.
Mars also has itsshare of volcanoes. Most of these volcanoes are shieldvolcanoes. The surface is littered with winding channels thatresemble river channels that have dried up over time. Scientistsbelieve that water once existed and caused the formation of thesechannels. It is said that, ” Mars remains the best candidate forlife in the solar system outside of the Earth,” and that is whatmakes Mars so interesting to scientists.Jupiter is the fifth planet and is the most massive of all Planets 6the planets in this solar system.
” Its mass represents morethan two-thirds of the total mass of all the planets, or 318times the mass of the Earth. Jupiters density is quite low atThe atmosphere of Jupiter contains water, ammonia, methaneand carbon. It is thought by scientists that there are threecloud layers. The wind activity on Jupiter is quite fierce andmoves in jet streams parallel to the equator. The weather onJupiter is still very hard for scientists to understand.
Thereis not enough information to truly understand how the weather isJupiter is most known by the normal citizen by the rings ithas. These ” rings are very diffuse. The ring particles mustgenerally be about as big as the wavelength of light, that is,only a few microns ” (Grolier, 1992). That is why these ringsare faint or diffuse. The rings are what Jupiter is known for.Saturn is a planet which is also known for its rings andwhen viewed has a yellow or grayish color. The color is from thegaseous atmosphere and the dust particles in that atmosphere. The atmosphere is mostly a clear hydrogen-helium atmosphere.
There are also traces of methane, phosphine, ethane, andacetylene. This atmosphere is much different than that of theSaturn orbits the sun with a period of 29.4577 tropicalyears. It is 1.427 billion Km away from the sun and is thereforea cold planet.
It has an equatorial diameter of 120,660 Km which Planets 7makes it the second largest planet in our solar system. The next planet is Uranus. The main problem scientists havewith Uranus is that, “the lack of visible surface features meansthat it is difficult to measure the rotation period of Uranus”(Hunt/Moore, 388, 1983). Uranus has an equatorial diameter of51,000 Km which is almost four times as much as Earth.
Theatmosphere is mostly methane gas and therefore the planet has ared tint or a blueish green color. Uranus also has rings butunlike Saturn these rings have almost no small particles. Scientists are not as concerned with this planet.Neptune is the last of the gaseous planets in our solarsystem.
Its atmosphere is much like Uranus’s because it ismostly helium and hydrogen. It also contains methane. Neptunehas a diameter of 49,500 Km and a mass 17.22 times that of theEarth.
It has an average density of 1.67 /cm^3 (Grolier, 1992).Neptune also has rings like its other gaseous partners, but theyare very faint. Not a great deal is known about Neptune. It iswidely studied by scientists and that makes it an importantThe final planet, which is also the smallest, and thefurthest away from the sun is Pluto.
This planet is very hard tosee therefore not a lot is known about its physicalcharacteristics. Scientists do know that it has a thin methaneatmosphere. Little is known about this planet because it is sofar away from the Earth and the sun. Scientists are alwayslearning new things and more data will arise in the future. Planets 8As one can see the planets of most importance are the onesclosest to the sun and Earth. Little is known about the far offplanets therefore it is hard to give them full recognition. Muchis known about Mercury, Venus, Earth, Mars, Jupiter and Saturn. The other three planets are not as well known as these six are.
Whether more planetary systems exist doesn’t really matter. There are still plenty of things we don’t understand about ourown solar system. Scientists will have their work cut out forthem in the future. Each and every planet has distinctdifferences and that helps show us how truly great God is. Theplanets will never fully be understood and will always be a greatBibliography:Planets 9Works SitedCattermole, P. (1995). Earth and Other Planets. New York: Oxford University Press.
Grolier Electronic Publishing, Inc. (1992).Hunt, G.
& Moore, P. (1983). Atlas of the Solar System. Chicago: Rand Mc Nally & Company.Morrison, D. (1993).
Exploring Planetary Worlds. NewYork: Scientific American Library.Thompson, G.
& Turk, J. (1993). Earth Science and theEnvironment. New York: Saunders College Publishing & HarcourtBrace College Publishers.