Dust devils ‘spotted’ at Mars probe’s landing site

In fact, NASA’s Mars Reconnaissance Orbiter, which is monitoring the site, has pinpointed the two dust devils at the centre of the landing ellipse, which measures nearly 20 by 100 kilometres across.

“It’s the low gravity and the fact that the surface gets warm and the energy is transferred into turbulence and uplift within the atmosphere,” the ‘New Scientist’ quoted Phoenix team member Ray Arvidson as saying.

Dust devils are created when vortices of air — set in motion when warm air rises from the surface on an otherwise still day — pick up dust from the ground. The dust reaches such great heights due to the Red Planet’s low gravity.

Despite their enormous height, the vortices are not powerful enough to endanger any spacecraft. “If we’re lucky, the occasional dust storm will help clear the dust off the deck and the solar panels,” Arvidson said.

The scientists estimate that dust devils will appear more and more often around Phoenix’s landing site in the coming months — that’s because the northern hemisphere is approaching summer and more vortices are expected to occur as temperatures rise.

The kilometre-high dust devils, which have been caught on camera previously by the Spirit rover, could provide a dramatic sight for Phoenix, which is expected to operate for about 90 days at a single spot in the flat, Green Valley.

“The topography should be pretty flat looking off into the horizon… so the dust devils should be easy to spot.

Phoenix team members will try to make a movie of any dust devils observed by the lander, just as was done by the Spirit rover,” Arvidson said.