MAVEN, or the Mars Atmosphere and Volatile Evolution spacecraft, has been circling Mars since last September. Last December, it witnessed an unusual aurora. As on Earth ,the spectacular colors of auroras are the result of the charged particles from solar storms crashing into the atmosphere. But Mars's atmosphere is thinner and its magnetosphere, which attracts charged particles, also weaker and patchier that Earth's. That made the December aurora pretty unusual, as New Scientist explains:
The new aurora, dubbed "Christmas lights" by the team because it occurred from 18 to 23 December last year, is different. It was seen in many different parts of the northern hemisphere and at much lower altitudes than previous auroras. "We're seeing it not connected to magnetic regions," says [mission leader Bruce] Jakosky. "We don't know if it is occurring only at the places we're observing, or if it is globally distributed."
MAVEN also witnessed a mysterious dust cloud as it was orbiting Mars, which you can read about in more detail at New Scientist. We've sent quite a few rovers to Mars's surface, but there's much to learn about what goes on in the planet's atmosphere. [New Scientist, NASA]
Top image: University of Colorado
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