Mars is famous for its duststorms, which can grow big enough to cover the entire planet. But did you know that it also has snowstorms? These storms can dump a lot of snow on the north polar cap during the bitterly cold winter, and now scientists say they can more accurately forecast them, it was reported yesterday, which would aid any future rover missions in these areas.
Generally, the polar caps on Mars are similar to those on Earth, with thick deposits of ice and snow. The Martian ones are a little different though; there is a permanent cap of frozen water, but this is covered by a larger cap of frozen carbon dioxide (aka dry ice) during the winter. During that time, temperatures can plunge below -128˚ C (-198˚ F), allowing carbon dioxide to freeze out as snow and ice.
As Dr. Paul Hartogh from the Max Planck Institute for Solar System Research (MPS) explains, “Mars’ seasonal ice has two different origins. A part of the carbon dioxide from the atmosphere condensates directly on the surface – similar to the way a layer of frost forms on Earth in cold, clear weather. Another part freezes in the atmosphere.”
At such low temperatures, the carbon dioxide freezes out as tiny ice crystals, forming clouds. “These clouds can be found north of 70 degrees northern latitude in all layers of the atmosphere up to a height of 40 kilometers,” Hartogh adds. The ice crystals then fall to the ground as snow.
Regular water-based snow as we know it is also possible though. The Phoenix lander, which landed near the Martian north pole in 2008, made the first ground-based measurements of water-ice crystals falling to the ground.
The simulations done for the new study are based on known climate models for Earth, but tweaked for Martian conditions. The results may help to reliably predict snowstorms on Mars, according to Dr. Alexander Medvedev from the MPS.
“Everyone knows from experience that on Earth reliable weather forecasts are only possible for a time span of five to seven days at most. It is simply impossible to calculate whether or not it will snow somewhere on Earth 20 or 40 days in advance. On Mars this is different. The simulations show that in certain regions on Mars snow falls can be predicted far in advance.”
“For missions to Mars aiming to explore these regions with rovers this is valuable information,” Hartogh adds. The rovers’ routes could be planned to avoid heavy snow storms.
Another good example of a phenomenon which is similar to what we see here on Earth, but with a unique alien twist to it. Whether dust or snow, these Martian storms are something that one would be wise to avoid as much as possible.
This article was first published on Examiner.com.