Mars has only very thin atmosphere, which contains mostly carbon dioxide (CO2). The surface pressure on planet is only 0,6% of average surface pressure at the sea level on Earth. The pressure on Mars is being changed according to seasonal changes. In winter the carbon dioxide freezes and then it is snowing and also it creates the polar caps. This process radically changes the composition of state of atmosphere – the carbon dioxide is disappearing. In summer the polar caps disappear or are getting smaller and the carbon dioxide is getting back into the atmosphere.
Methane in martian atmosphere is displayed in the image above (click for better resolution)
The atmosphere of Mars contains large amount of fine dust particles. Wind blowing at Mars makes dust storms. There are known also small kind of “hurricanes”, called dust devils.
Dust in the atmosphere of Mars was scanned with the THEMIS camera on board of Mars Odyssey – picture below (credits – CalTech, Arizona University):
Color scale displays amount of dust, where 1 means highest and the 0 means lowest.
Composition of atmosphere of Mars:
95,32 % – carbon dioxide
2,7 % – nitrogen
1,6 % – argon
0,13 % – oxygen
0,07 % – carbon monoxide
0,03 % – water vapor
particles – neon, crypton, xenon
Atmospheric pressure on Mars is 1 – 9 milibars, average it is 7 mb
Temperatures of martian atmosphere
Comparison of atmosphere of Mars with atmosphere of Earth and temperature evolution relative to elevation is displayed below:
Martian clouds are made by small pieces of ice and frozen carbon dioxide:
Sources and image credits: NASA