It Snows On Mars

It Snows On Mars

It… it snows on Mars. This is amazing.

Researched published this week in Nature Geoscience details a study that simulates Martian meteorology, and shows that localised storms of rapidly falling snow — “microbursts” of snowfall – occur on Mars due to cooling of cloud water-ice particles during the night.

Because the atmosphere of Mars is cold and thin, water-ice clouds can form despite the limited amount of atmospheric water vapour compared to Earth. However, it had been thought that any snow precipitation that fell from these clouds did so as slowly settling particles, rather than in rapidly descending storms.

In this research, Aymeric Spiga lead a team that used an atmospheric model to simulate the weather on Mars. They foundthat cooling of water-ice cloud particles during the cold Martian night can create unstable conditions within the cloud, triggering the development of a descending plume of snow.

These turbulent storms, which can only form at night, act to vigorously mix the atmosphere and, in some places, deposit snow on the Martian surface. The proposed process also sheds light on the previously unexplained precipitation signatures detected by NASA’s Phoenix lander.

The researchers say that Martian snowstorms are analogous to small localised storms on Earth called microbursts, in which cold dense air carrying snow or rain is rapidly transported downwards from a cloud.

[Nature Geoscience]