Mars has bitterly blizzards in the night, according to new models of Martian weather.
The snow falls fast on Mars, leading to 'microbursts' of water-ice particles fall during the Martian night. The snow falls hundreds of times faster than predicted by previous data, according to a study in the journal Nature Geoscience.
"It's the first time anyone has shown that snowstorms, or water-ice microbursts, occur presently on Mars," study author Aymeric Spiga, of the University Pierre and Marie Curie in Paris, told New Scientist.
"Any snow particles formed were thought to fall only very slowly through their own weight."
The researchers used data from NASA's Mars Global Surveyor and the Mars Reconnaissance Orbiter to create detailed computer models of the Martian climate. Previous models used data from NASA's Phoenix rover that landed in 2008, which was the first to measure snowfall on Mars.
"Clouds and snowfall have emerged in recent years as central players in the water cycle and climate of Mars," Paul Hayne, a geophysicist at NASA's Jet Propulsion Laboratory who wasn't involved in the research, told Science magazine.
Very strong winds could be pulling the snow down, rather than gravity, according to Spiga and his colleagues. The snow is thought to fall at speeds of up to a mile every 10 minutes.
"This is an important discovery because it allows us to understand the conditions under which snowfall can deposit water ice on the surface," Hayne said.
But the snow may not always reach the surface, Spiga argues. The storm could be what is known as a 'virga', where the snow turns into a gas before it hits the ground. Only if the winds are very strong would the snow reach the ground to sprinkle Martian soil.
Whether or not these mechanisms explain the snow detected by Phoenix is not yet clear, its operators have said.
"The streaks we saw up there could be quite different than the mechanisms at 25 degrees latitude," Peter Smith of the University of Arizona and principal investigator of the Phoenix mission told The Verge. "It's comparing the weather in northern Alaska to down in Mexico City."
Further studies to attempt to replicate the findings would offer stronger support for the theory. Ideally perhaps a rover might one day too be able to witness snow falling on Mars.