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Dust Devils on Mars
04.11.2005
 
What started out as a couple of dust devils first spied by the Spirit rover a couple of weeks ago has now turned into a swarm of dust devils wheeling across the plains of Gusev Crater almost every day.

This picture shows five stacked images of a horizontal, sandy plain tilted at a slight angle from lower left to upper right. On the left side of the top image, a plume of dust extends upward from the surface toward the sky. In the next image below that, the same plume of dust has moved a little farther to the right. In the third, fourth, and fifth images, the same plume of dust has moved a little farther to the right each time. Image to right: Dust Devils on Mars Spirit took this image of several dust devils in Gusev Crater using its navigation cameras on sol 433 (March 21, 2005). Image credit: NASA/JPL
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So far, the dust devils are about the same size as those that whip up desert dust and sand in the southwestern United States, though orbital images in past years have detected dust devils in many places on Mars that are up to several kilometers (a few miles) tall, says Shane Thompson, Research Technician with the Planetary Geology Group at Arizona State University.

Accompanied by Wind

NASA's Spirit rover spotted the first dust devil of the Mars Exploration Rover mission on martian sol, or day, 421 (March 10, 2005). The dust devil was observed the day after martian winds cleared the rover's deck and increased the amount of power the rover harvested from sunlight shining on its solar panels.

This picture shows four stacked images of a horizontal, sandy plain tilted at a slight angle from lower left to upper right. In the top image, a plume of dust extends upward from the surface toward the sky. In the next image down, the same plume of dust is a little farther to the right. In the third, the same plume of dust has become smaller and has moved a little farther to the right. In the fourth image, the plume of dust has dissipated. Image to right: More Dust Devils Spirit took these images of dust devils in Gusev Crater with its navigation cameras on sol 433 (March 21, 2005). Image credit: NASA/JPL
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Sign of Spring?

Rover science team member Ron Greeley, Director of the Planetary Geology Group, has been tracking and studying dust devil characteristics in detail on both Mars and Earth for the past couple of years. Scientists believe the small cyclones are seasonal, perhaps linked to wind storms that occur in the martian spring.

"We're trying to determine whether dust devils play a small or large role in changing the surface of Mars in the short-term," says Thompson.

This picture shows a magnified view of a plume of dust rising up from the surface of a flat plain and partially obscuring the view of martian sand and distant hills beyond. Image to right: Biggest Dust Devil So Far Spirit took this image of the biggest dust devil encountered on sol 433 (March 21, 2005). Image credit: NASA/JPL
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More at Mars Rovers or Mars Exploration Program .