Question

What is an envelope of gas surrounding a body in space?

Answer 1

Obviously, its the atmosphere

Answer 2

The answer can be of various types. Depends on what kind of celestial body you are talking about. The envelope of air that surrounds earth and the other planets( though only a few) is known as atmosphere. This kind of air pockets and envelopes are also created during the formation of stars and during their destruction. This kind of envelope usually plays a role of protecting or rather "blanketing" the body with "heavenly forces", and does not meteorites inside. Something similar to the way earth's atmosphere works.

Hope this helps,

HunterGirl