planets

            
             The Planets and the Solar System.
             Planets 2.
             " A planet is a celestial body that revolves around a.
             central star and does not shine by its own light " (Grolier,.
             1992). The only planetary system that is known to man is our.
             solar system. It is made up of nine planets which range in size.
             and make-up. The nine major planets in our solar system are.
             Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and.
             Pluto. There are also many other minor planets which are also in.
             our solar system, but they are unimportant compared to the nine.
             major planets. In this paper I will discuss the planets and how.
             they are each unique.
             Mercury which is the planet that is closest to the sun is.
             the first planet I will discuss. Mercury is the smallest of the.
             inner planets. It is speculated that the heat from the sun made.
             it impossible for the gases present to become part of the.
             planetary formation. The surface of Mercury is extremely hot. .
             It is approximately 470 degrees celsius on the surface and is.
             thought to be even hotter at the two " hot spots." These " hot.
             spots " are on opposite ends of the equator. It is the heat of.
             the surface that makes it impossible for Mercury to have any type.
             of atmosphere.
             Mercury orbits the sun once every 88 days and has a true.
             rotation period of 58.6 days. " It is the closest planet to the.
             sun and therefore orbits faster than any other planet ".
             (Thompson/Turk, 542, 1993). It is said that Mercury rotates.
             three times for every two trips around the sun, so that during .
             Planets 3.
             every alternate perihelon passage the same face points directly.
             at the sun. " Geologically, the most remarkable features of.
             Mercury are compressional cliffs or faults, just the sort of.
             wrinkles that might form in the crust if the interior of the.
             planet shrank slightly " (Morrison, 74, 1993).