Free Astronomy Magazine January-February 2016

SPACE CHRONICLES MAVEN reveals speed of solar wind stripping martian atmosphere T he MAVEN mission has identi- fied the process that appears to have played a key role in the transition of the Martian cli- mate from an early, warm and wet environment that might have sup- ported surface life to the cold, arid planet Mars is today. MAVEN data have enabled researchers to deter- mine the rate at which the Martian atmosphere currently is losing gas to space via stripping by the solar wind. The findings reveal that the erosion of Mars’ atmosphere increa- ses significantly during solar storms. The scientific results from the mis- sion appeared in the Nov. 5 issues of the journals Science and Geophysi- cal Research Letters . “Mars appears to have had a thick atmosphere warm enough to sup- port liquid water which is a key in- gredient and medium for life as we currently know it,” said John Gruns- feld, astronaut and associate admin- istrator for the NASA Science Mis- sion Directorate in Washington. “Understanding what happened to the Mars atmosphere will inform our knowledge of the dynamics and evolution of any planetary atmo- sphere. Learning what can cause changes to a planet’s environment from one that could host microbes at the surface to one that doesn’t is important to know, and is a key by NASA A rtist’s rendition of a solar storm hitting Mars and stripping ions from the upper atmosphere. [NASA/GSFC]