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New Auroras And Dust Clouds of Mars Puzzle Scientists

| 18 Mar 2015 20:45

Just when we thought Mars was figured out, the MAVEN spacecraft found auroras and dust clouds that just don't make sense.

Even if Mars One doesn't end up working out, we're never going to quite get over Mars. Our nearest planetary neighbor is much like a first significant other - captivating to behold yet utterly alien to everything you've experienced. And the longer we look the more this proves true, like how the planet has auroras (such as Earth's Northern Lights) that don't behave much like what you'd see on our planet.

The auroras were spotted just before Christmas 2014 by NASA's Mars Atmosphere and Volatile Evolution spacecraft, or MAVEN. MAVEN's Imaging Ultraviolet Spectrograph observed that they weren't so unfamiliar from Earth's except for one difference - they reach far deeper into the inner atmosphere than anyone expected. On Earth our magnetic field reaches beyond the inner atmosphere, which the sun's particles need to break past to create the auroras. But Mars hasn't had a magnetosphere for billions of years - which means solar particles can hit the atmosphere directly and reach deeper than they would otherwise.

Even that doesn't explain everything however, since the aurora reaches much deeper into the atmosphere than anywhere else on Mars. "What's especially surprising about the aurora we saw is how deep in the atmosphere it occurs - much deeper than at Earth or elsewhere on Mars," the University of Colorado's Arnaud Stiepen explained. "The electrons producing it must be really energetic."

But it's the non-shiny displays MAVEN's picking up that will be more significant to scientists. For example: Not only has MAVEN picked up a huge dust cloud orbiting the planet, it's far higher than NASA would have predicted - sitting 93 to 190 miles above the planet. Scientists think the dust may have come from Martian moons, solar wind, or even comet debris, but have no idea what actually brought it into orbit like that. We don't even know if it's a long-term phenomenon, just that it's been floating there for as long as MAVEN was watching.

MAVEN still has eight months left in its mission, so hopefully we'll learn a lot more about the red planet before it moves on.

Source: Washington Post

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