Planets are large sphere of material that orbit the Sun. Some planets are primarily rocky in composition. Others are primary liquid or gas. There are eight planets in our solar system:
- Mercury
- Venus
- Earth
- Mars
- Jupiter
- Saturn
- Uranus
- Neptune
The first four planets are known as terrestrial planets. They are Earth-like in that they are primarily composed of rock.
Terrestrial planets (credit: NASA/Lunar and Planetary Institute)
The later four are known as Jovian planets, because they are similar to Jupiter (Jove). They are more voluminous than terrestrial planets. However, most of that volume comprises liquids and gasses.
Gas interiors of Jovian planets (credit: NASA/Lunar and Planetary Institute)
There are also several large minor planets such as Pluto.
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