A very thin layer on a planet's or moon's surface, the main body of
a gas giant, atmospheres are condensations of low mass molecules,
such as hydrogen, or oxygen in a gas or liquid form. They can also be
signature for very many things about an object - for instance -
life...... Our planet's atmosphere is polluted with oxygen - a key
signature. ![Read More](https://webarchive.library.unt.edu/web/20080916094740im_/http://solarsystem.nasa.gov/images/arrow_blueonwhite.gif)
More Themes ![More Themes](https://webarchive.library.unt.edu/web/20080916094740im_/http://solarsystem.nasa.gov/images/arrow_blueonwhite.gif) |