Snow Falls on Mars in the Summer

The globe of Mars, as seen in a mosaic of images from the Viking orbiters. In the Martian north, summer brings a nightly dusting of snow. This surprising scene comes courtesy of new simulations of flip-flopping layers in the Martian atmosphere, which mix more vigorously than expected and produce stormy weather. Though still virtual, the snow shower fits quite well with an observation made by a robot placed on Mars in 2008--and it may offer an explanation for how a very different type of snow falls out of the red planet's polar skies. If the simulations are correct, the summertime snow on Mars happens in bursts that can last for several hours, scientists report in a study describing the find published today in the journal Nature Geoscience.