The Planets and the Solar System " A planet is a celestial body that revolves around a central star and does not shine by its own light " (Sipiera 15). 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 that 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 that 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). It is said that Mercury rotates three times for every two trips around the sun, so that during every alternate perihelion 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). It is speculated that it was the solidification of Mercury's metallic core that caused this global shrinkage. Mercury is also " . . . enriched in metal or depleted of rock " (Morrison 74). It is also be...
