A planet's climate is decided by its mass, its distance from the sun and the composition of its atmosphere. Mars is too small to keep a thick atmosphere. Its atmosphere consists mainly of carbon dioxide, but the atmosphere is very thin. The atmosphere of the Earth is a hundred times thicker.
Using this item and referring to it is encouraged, and please use
it in presentations, web pages, newspapers, blogs and reports.
For any form of publication, please include the link to this
page and give the creator credit
(in this case Philippe Rekacewicz, UNEP/GRID-Arendal)
If the high-resolution file is not available, please contact
firstname.lastname@example.org for request and
permission for usage.