Secondary atmosphere

From Wikipedia, the free encyclopedia

A secondary atmosphere is an atmosphere of a planet that did not form by accretion during the formation of the planet's sun.

A secondary atmosphere instead forms from internal volcanic activity, or by accumulation of material from comet impacts.

Earth has a secondary atmosphere. It is characteristic of terrestrial planets, such as Mercury, Venus and Mars. Secondary atmospheres are relatively thin when compared to primary atmospheres like the one found on Jupiter.