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The Martian Atmosphere

November 10, 2015

A space probe orbiting Mars is sending back evidence of what happened to its once-thick atmosphere.



An artist’s depiction of the Mars MAVEN orbiter. (NASA)


Where did Mars’ CO2 go? I’m Bob Hirshon and this is Science Update.

Billions of years ago, Mars had a thick atmosphere, rich in carbon dioxide, and plenty of surface water, which possibly could have harbored life. But solar storms slowly stripped CO2 from Mars’ upper atmosphere. This according to an analysis in Science magazine of data gathered by NASA’s MAVEN space probe, which is currently orbiting the Red Planet.

BRUCE JAKOSKY (University of Colorado):

If you look at Mars today, it’s a very cold, dry planet. It has a very thin CO2 atmosphere. And we’re trying to understand why.


That’s University of Colorado atmospheric scientist Bruce Jakosky.


The rate of loss is relatively slow today, but over time we think that this could account for the loss of a very thick early atmosphere. 6


He says earth’s atmosphere is protected by its magnetic field, which keeps solar winds from sucking its CO2 into space. I’m Bob Hirshon, for AAAS, the science