NASA unveils seasonal dust storm pattern on Mars

NASA’s Mars orbiters have unveiled a pattern of large regional dust storms occurring at about the same times each year, an advance that may help predict these hazardous events during future robotic and human missions to the red planet.

After decades of research to discern seasonal patterns in Martian dust storms from images showing the dust, but the clearest pattern appears to be captured by measuring the temperature of the red planet’s atmosphere.

For six recent Martian years, temperature records from  NASA Mars orbiters reveal a pattern of three types of large regional dust storms occurring in sequence at about the same times each 

year during the southern hemisphere spring and summer. Each Martian year lasts about two Earth years.

“When we look at the temperature structure instead of the visible dust, we finally see some regularity in the large dust storms,” said David Kass of NASA’s Jet Propulsion Laboratory in the US.

“Recognising a pattern in the occurrence of regional dust storms is a step toward understanding the fundamental atmospheric properties controlling them,” he said. Dust lofted by Martian winds links directly to atmospheric temperature: The dust absorbs sunlight, so the Sun heats dusty air more than clear air.

In some cases, this can be dramatic, with a difference of more than 35 Celsius degrees between dusty air and clear air.