Ask A Scientist© Astronomy Archive

Author:      stan f kuba and brian p laporte
Other than nitrogen, could you please tell me what the planet mars is made
of (please do not say cheese!)?

Response #:  1 of 1
Author:      asmith
The atmosphere has lots of carbon dioxide.  The ground seems to be the same
kinds of minerals as the Earth has, with lots of silicates (silicon and
oxygen and other stuff mixed in) and also a dash of iron oxides to give it
that reddish color.  Mars does seem to be somewhat lower in water than the
Earth, probably because its original water got decomposed into oxygen and
hydrogen, and the hydrogen escaped because it was so light.