Cosmology
Text only © 1998 - 2001
Paul J. Marquard.
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This web site funded
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Space Grant Planetary & Space
Science Center, NASA
Grant #NGT40008.
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As we study the planets, astronomers like to categorize the planets into two categories. The first category is the terrestrial planets. The second category is the Jovian planets. The terrestrial planets include Mercury, Venus, Earth, and Mars. These planets have solid surfaces, with the last three also having an atmosphere. Their size, radius, and density are all similar. The Jovian planets include Jupiter, Saturn, Uranus, and Neptune. These planets are also called gas giants. They are much larger in radius than the terrestrial planets, and the majority of their volume is composed of gas. In this section we concentrate on the terrestrial planets.
This page was last updated on 06/13/01.