The atmosphere of which of these Solar System bodies is primary (as opposed to secondary) in origin?
A) Venus
B) Earth
C) Saturn's moon Titan
D) Saturn
E) Mars

Question

Quizplus · Accepted Answer

Primary atmospheres are those that a planet or moon captures directly from the solar nebula during its formation. Saturn, being a gas giant, has a primary atmosphere composed mainly of hydrogen and helium, which it captured from the solar nebula.

The Atmosphere of Which of These Solar System Bodies Is