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Last month, we were excited to share an image of a twister on Mars that lofted a twisting column of dust more than 800 meters (about a half a mile) high. We now know that’s nothin’ — just peanuts, chump change, hardly worth noticing. The Mars Reconnaissance Orbiter has now spotted a gigantic Martian dust devil roughly 20 kilometers (12 miles) high, churning through the Amazonis Planitia region of northern Mars. The HiRISE camera (High Resolution Imaging Science Experiment) captured the event on March 14, 2012. Scientists say that despite its height, the plume is just 70 meters (70 yards) wide.
Yikes! After seeing trucks thrown about by the tornadoes in Dallas yesterday, it makes you wonder how the MER rovers and even the Curiosity rover would fare in an encounter with a 20-km high twister.
The image was taken during late northern spring, two weeks short of the northern summer solstice, a time when the ground in the northern mid-latitudes is being heated most strongly by the sun.
Dust devils are spinning columns of air, made visible by the dust they pull off the ground. Unlike a tornado, a dust devil 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.
Obviously, conditions were more than just right to create such a whopper.
Source: JPL
Martian tornadoes may be big, but given the Martian atmosphere there can’t be much to them. I daresay the rovers would manage just fine with the winds (though maybe not the dust).
@ToSeek: on the contrary, these are what has been clearing the dust off of the rovers’ solar panels, allowing them to keep working far longer than anticipated.
yes. the low density of the ‘air’ would likely have little effect in the rovers but the high velocity lifts the dry dust away. dry dust that accumulates slowly on the horizontal surfaces. that’s just what they need to spiff up.
test
Nancy – your articles for Universe Today have twice referred to dust devils on Mars as ‘tornadoes’ in the headlines and bodies of the articles. They are NOT tornadoes. They are dust devils. A tornado is a cumulus cloud driven vortex, known at present only on Earth, which may or may not touch the ground. They are big and powerful, as we know all to well.
A dust devil is a clear sky vortex driven by ground heating, has no associated cloud structure, and can be difficult to detect if it doesn’t pick up dust (or, on Earth, trash). They are small, with characteristic winds much less than tornadoes.
Tornado = problem. Dust devil = nuisance. Dust devil does not = little tornado. They are separate things, with different causes. The Wiki articles on each are good.
Kinda makes you wonder what both would be like on super earths with oxy-nitrogen atmospheres, doesn’t it?
Regards, John Mendenhall, Established Member.
Perhaps it is an add choice of use in the headline, but I’m sure the author knows the difference between the two seeing as she refers to them as ‘Dust Devils’ in the article.
Regards, Dampe, Grocery Store Assistant
Artistic license in reporting? Eh, excusable. We’ve seen worse on the cover of Sky and Telescope. We just don’t want to give the public the impression that they are the same thing. This is, after all, a hard science forum.
Artistic license in reporting? Eh, excusable. We’ve seen worse on the cover of Sky and Telescope. We just don’t want to give the public the impression that they are the same thing. This is, after all, a hard science forum.
Well someone stepped from the crowd
He was 19 miles high
He shouts “We’re tired and disgusted,
so we paint red through the sky.”
Can they tell what the wind speeds are? How common are tonadoes on Mars?