Why did the terrestrial planets lose the majority of the gas in their primary atmospheres?
A) They were too hot and their escape velocities too low to hold onto them.
B) The solar wind was too strong and blew these gasses off the planets.
C) Their high surface temperatures made the gas chemically react with the rock.
D) The centrifugal force from the planets' fast rotation rates made them fly off.
E) The initial gases were so heavy when the planet differentiated that they sank to the core.

Question

Quizplus · Accepted Answer

Terrestrial planets are much smaller than gas giants, and so their weak gravitational force coupled with high temperatures meant that they were unable to hold onto their primary atmospheres. The lighter gases, such as hydrogen and helium, escaped from the planets' gravitational pull and dissipated into space.

Why Did the Terrestrial Planets Lose the Majority of the Gas