Question

which statement accurately describes the atmospheres of the inner planets?
mars has no atmosphere.
mercury has a thick atmosphere.
the atmospheres of mars and venus are similar in composition.
the atmospheres of earth and venus are similar in composition.

Explanation:

• Mars has a thin atmosphere, so the first option is wrong.
• Mercury has an extremely thin, negligible atmosphere, so the second option is wrong.
• Mars' atmosphere is mostly carbon dioxide (~95%), and Venus' atmosphere is also over 96% carbon dioxide, making their compositions similar.
• Earth's atmosphere is ~78% nitrogen and ~21% oxygen, while Venus' is nearly all carbon dioxide, so their compositions are not similar.

Answer:

C. The atmospheres of Mars and Venus are similar in composition.