MAVEN measures Mars’s rate of atmosphere loss and spots new type of aurora

Atlantic : On Thursday, NASA held a press conference announcing recent findings from the Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft. The primary finding was that the normal rate of atmosphere loss on Mars is roughly 100 g/s and that during solar storms that rate increases by at least a factor of 10. Early in 2015, MAVEN observed the effects on Mars of an X-class solar flare, one of the largest ever seen, which created an unusual aurora deep in the Martian atmosphere. The extreme electromagnetic impact of the flare significantly altered the structure of the planet’s magnetosphere and allowed much more of Mars’s atmosphere to escape. The MAVEN team proposes that such storms were likely the driving force behind Mars’s early loss of atmosphere. The aurora itself appears to have been caused by the remnant magnetism in the Martian crust, as opposed to Earth’s aurorae, which are driven by the magnetism from Earth’s rotating iron core. As a result, the Martian aurorae could span nearly the entire planet’s sky.