Mars' Atmosphere Stripped By Solar Winds, NASA Says - by Kenneth Chang/ Space & Cosmos/ International New York Times/ The New York Times/ nytimes.com
"The air on Mars — what there is of it — is leaking away, about half a pound a second sputtering into space, scientists announced on Thursday.
The planet’s early atmosphere is thought to have been as thick as or thicker than Earth’s today, and even over the 4.5-billion-year history of the solar system, that slow leak would not explain how it atrophied to its current wisps.
But new readings from NASA’s Mars Atmosphere and Volatile Evolution mission — Maven, for short — show that when Mars is hit by a solar storm, the ferocious bombardment of particles from the sun strips away the upper atmosphere much more quickly.
That could help explain the disappearance of the atmosphere. The sun during its youth was more unsettled, with many more solar storm eruptions, and it shone brighter in the ultraviolet wavelengths that also help knock atoms out of Mars’ atmosphere.
“What this tells us is loss through space has been an important process,” said Bruce M. Jakosky, a scientist at the Laboratory for Atmospheric and Space Physics at the University of Colorado and the principal investigator for the Maven mission..."
An artist's rendering of a solar storm approaching Mars. Credit NASA Goddard Space Flight Center
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