Ice Giant Planets
- Uranus and Neptune are 15 times to 17 times the mass of the Earth, respectively.
- They are made of the same stuff as comets - ice and rock.
- They are far enough from the Sun that ice is a rock.
- Thus, they formed from solids like terrestrial planets.
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- Density is about 11/2X that of water.
- Probably the same as the cores of the gas giants.
