NASA spacecraft spots 12-mile-high Martian dust devil
In April, 2012, NASA released an image showing a Martian dust devil roughly 12 miles (20 kilometers) high. NASA’s Mars Reconnaissance Orbiter – which has been orbiting the Red Planet since 2006 – caught sight of this beauty as it whirled on the sands of the Amazonis Planitia region of northern Mars on March 14, 2012.
The spacecraft captured the image late northern spring, two weeks short of the northern summer solstice, which took place on March 30, 2012. Around this time, the ground in the northern mid-latitudes of Mars is subject to the sun’s most direct rays of light and heat.
The dust devil was tall, but it was relatively skinny. The width of the plume was about three-quarters of a football field wide (70 yards, or 70 meters).
Dust devil – or whirlwinds – form on Earth, too, but Martian ones can be much bigger. The Viking orbiters first photographed dust devils on Mars in the 1970s. In 1997, the Mars Pathfinder lander detected a dust devil passing over it. I especially like the animated gif below. It’s from the Mars rover Spirit in 2005.
The counter in the bottom-left corner indicates time in seconds after the first photo was taken in the sequence. At the final frames, you can see that the dust devil left a trail on Mars’ surface. Three other dust devils also appear in the background.
A dust devil on Earth or Mars typically forms on a clear day when the ground is heated by the sun, warming the air just above the ground. As heated air near the surface rises quickly through a small pocket of cooler air above it, the air may begin to rotate, if conditions are just right.
Bottom line: NASA released an image on April 4, 2012 showing a Martian dust devil roughly 12 miles (20 kilometers) high, taken by NASA’s Mars Reconnaissance Orbiter about two weeks ago.