Solar System

SOLAR SYSTEM

Our solar system is composed of planets, comets and asteroids along with other space debris that orbits the star we call the sun. Formed more than 4 1/2 billion years ago.All of theobjects that comprise the solar system originated from a huge cloud of gases and dust called a nebula. This cloud began to spin slowly and then faster, with the matter in the center spinning andcollapsing in on itself. This became the sun. Other pockets of matter spun off from this cloud and became the planets. Some planets were large enough to use their gravitational forces to attract largeamounts of gases. These became the giant planets that include Jupiter, Saturn, Uranus and Neptune. These bodies rotated around the central sun in orbits, thus becoming the solar system.

The sun makes upalmost all of the matter in the solar system percentagewise--more than 99 percent. The planets would be orbiting the sun counterclockwise, with Mercury closest to the sun and dwarf planets such asPluto farthest out. Earth would be the third planet from the Sun, with Venus the second. Mars would be fourth with a belt of space debris called asteroids next, perhaps as many as millions of themranging in size from hundreds of miles across to microscopic bits. The giant planets Jupiter, Saturn, Uranus and Neptune would follow in that order, with the dwarf planets beyond them.The inner fourplanets are much smaller than the outer four. These planets have dense, rocky cores, and only Earth and Mars have moons orbiting them. The outer planets have gaseous make-ups, mostly helium and hydrogen andice.

Mercury is the innermost of the eight planets in the Solar System. It is also the smallest. Since there is no real atmosphere, just a low, thin collection of ionized gases, there is no real"weather". The surface temperature, however is extremely hot when you're on the sunny side, and extremely cold when you're on the shady side.Venus is the second planet from the Sun and it has an...