May 11, 2015
Dr. Tony Phillips
A map of MAVEN’s Imaging Ultraviolet Spectrograph (IUVS) auroral detections in December 2014 overlaid on Mars’ surface. The map shows that the aurora was widespread in the northern hemisphere, not tied to any geographic location. The aurora was detected in all observations during a 5-day period. Credits: University of Colorado
This isn’t the first time a spacecraft has detected auroras on Mars. Ten years ago, the European Space Agency’s Mars Express found an ultraviolet glow coming from “magnetic umbrellas” in the southern hemisphere.
Unlike Earth, Mars does not have a global magnetic field that envelops the entire planet. Instead, Mars has umbrella-shaped magnetic fields that sprout out of the ground like mushrooms, here and there, but mainly in the southern hemisphere. These umbrellas are remnants of an ancient global field that decayed billions of years ago.
“The canopies of the patchwork umbrellas…
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