Mars dust devils
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Dust devils seen by the Spirit rover
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Dust devils are spinning columns of wind that move across the landscape,
pick up dust, and look somewhat like miniature tornadoes. Dust devils occur
commonly in dry and desert landscapes on
Earth, as well as Mars. They form when the
ground heats up during the day, warming the air immediately above the surface.
As the warmed air nearest the surface begins to rise, it spins. The spinning
column begins to move across the surface and picks up loose dust. The dust
makes the vortex visible. On Earth, dust devils typically last for only
a few minutes.
When dust devils pass over the surface of Mars, they leave dark, criss-crossing
streaks on the land. They can cross over hills, run straight across dunes
and ripples, and go through fields of house-sized boulders. The dust devils
remove bright dust from the terrain, revealing a darker surface underneath.
The dust devils in the photos shown here were recorded by the Mars
Exploration Rover Spirit in Gusev Crater
on Apr. 15 and 18, 2005. Related entry
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