dipper@utastro.UUCP (Debbie Byrd) (11/10/84)
The worlds in the outer part of the solar system are different from the planets that orbit nearer the sun. More -- after this. November 10 Order in the Outer Solar System The four inner planets of the solar system -- Mercury, Venus, the Earth and Mars -- are called the terrestrial worlds -- because they are made of stuff similar to what makes up the Earth. Between Mars and the largest planet Jupiter lies the asteroid belt -- where thousands of small rocky asteroids follow their individual paths around the sun. The asteroid belt provides a convenient dividing line between the smaller terrestrial worlds and the four giant planets of the outer solar system. Jupiter, Saturn, Uranus and Neptune are all gigantic whirling balls of gas -- much larger than the Earth -- located in the outer solar system. Each of the giants is at the center of its own system of moons -- each system with its own peculiarities. And all of the gas giants -- with the exception of Neptune -- are known for certain to be encircled by systems of rings. The farther a planet is from the sun in our solar system -- the longer it takes to move around the sun. Earth moves much faster around the sun than its four big brother worlds. Right now it happens that the four gas giants are on the other side of the sun from Earth -- some of them hidden from our sight by the solar glare. Early Sunday morning the second largest planet -- Saturn -- will be directly on the other side of the sun from the Earth -- in what's known as a conjunction -- when the Earth, the sun and Saturn will be in a straight line. Script by Diana Hadley. (c) Copyright 1983, 1984 McDonald Observatory, University of Texas at Austin