Question

identifying planets
planet a | planet b
atmosphere is mostly carbon dioxide. | atmosphere is rich in oxygen.
surface is red. | surface has liquid water.
it has a few clouds. | it has many clouds.
what is the identity of planet a?
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what is the identity of planet b?
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Explanation:

For Planet A: The atmosphere is mostly carbon dioxide, the surface is red, and it has a few clouds. These characteristics match Mars. Mars has a carbon - dioxide - rich atmosphere, a reddish surface (due to iron oxide), and sparse clouds.
For Planet B: The atmosphere is rich in oxygen, the surface has liquid water, and it has many clouds. These features are consistent with Earth. Earth has an oxygen - rich atmosphere (due to photosynthesis), liquid water on its surface, and a relatively cloudy atmosphere.

Answer:

Planet A: Mars
Planet B: Earth