Snow

Mars May Have Snowstorms at Night

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When you think about Mars, you probably imagine a vast, red desert, deathly still and sapped of moisture. While that's mostly true, there some water there — it's just in the form of ice and vapor. In August of 2017, researchers learned of another way the Red Planet isn't all that stagnant: it may have snowstorms.

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This is a visualization of the topography near the Martian north pole as measured with the MOLA instrument.

Walkin' In A Martian Wonderland

Just like Earth, Mars has an atmosphere. It's much thinner than ours — about 100 times thinner, in fact — but it's still substantial enough to get its share of wind, ice clouds, and even snow. Until recently, scientists believed that Martian snowflakes fell incredibly slowly, gradually accumulating until they were just large enough to drift toward the ground at barely 2 kilometers a day.

But recent observations didn't match up with that. While analyzing data from NASA's Mars Global Surveyor and Mars Reconnaissance Orbiter spacecraft, planetary scientist Aymeric Spiga and his colleagues noticed something strange. In the dead of night, heat was mixing in the atmosphere near the Martian surface — something that's regularly seen during the day in full sunlight, but not at night.

After spending a few years developing a model to simulate Martian weather, the researchers discovered what was going on. When the ice particles in the clouds cool at night, they can generate unstable turbulence, leading to strong winds — we're talking vertical plumes gusting at 22 mph (36 km/h), the kinds of speeds seen during moderate thunderstorms here on Earth. That makes them a bit like microbursts, the sudden, violent downpours we get on this planet.

Dust In The Wind

This shows that there's more to the Martian atmosphere than meets the eye. The fact that these researchers now have a way to model weather on the Red Planet means that we may have new discoveries waiting to be found. "Since you have these powerful winds, these are able to vigorously mix anything, such as heat, water, methane, ozone, dust," Spiga told Space.com. "We can now use this data to see what impact these winds have on, say, how water moved from one region to another on Mars in the present and past."

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The Weather on Mars

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