outer planet

astronomy

Learn about this topic in these articles:

In solar system: Planets and their moons
) In contrast, the four outer planets, also called the Jovian, or giant, planets—Jupiter, Saturn, Uranus, and Neptune—are large objects with densities less than 2 grams per cubic cm; they are composed primarily of hydrogen and helium (Jupiter and Saturn) or of ice, rock, hydrogen, and helium (Uranus and Neptune).…
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In solar system: Formation of the outer planets and their moons
This general scheme of planet formation—the building up of larger masses by the accretion of smaller ones—occurred in the outer solar system as well. Here, however, the accretion of icy planetesimals produced objects with masses 10 times that of Earth,…
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