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NASA / JPL-Caltech / Univ. of Arizona
A towering dust devil casts a serpentine shadow over the Martian surface in this image, acquired on Feb. 16 by the High Resolution Imaging Science Experiment on NASA's Mars Reconnaissance Orbiter.
A Martian mini-tornado caught on camera by NASA's Mars Reconnaissance Orbiter brings new meaning to the word "twister."
This isn't the first dust devil to show up on Martian imagery. The whirlwinds have been photographed by NASA probes for more than 30 years, and in some places, the Red Planet's landscape is heavily crisscrossed by dust devil tracks. In 2005, the Spirit rover's time-lapse view of multiple dust devils was made into a movie. But this picture, taken on Feb. 16 as the orbiter passed over the Amazonia Planitia region of northern Mars, has to rank among the most artistic of the dust devil delights.
Scientists estimate that the dust devil rose to a height of more than half a mile (800 meters), with a plume that's about 30 yards (meters) in diameter. A westerly breeze adds a delicate arc to the plume, and the afternoon sun creates a curving, stretched-out shadow.
Dust devils on Mars, like their cousins on Earth, are spinning columns of air that are made visible by the dust they stir up. They typically arise on a clear day when the ground is heated by the sun. As the atmospheric layer near the surface warms, air rises through a pocket in the cooler layer above it, taking on a spin when the conditions are just right.
Martian air is much thinner than our earthly atmosphere, and composed almost entirely of carbon dioxide. But the Red Planet's winds can still pack a huge punch. Over the years, NASA's rovers have benefited from wind-driven "cleaning events" that sweep the dust off their power-generating solar panels. Last month, the Opportunity rover underwent a slight cleaning that put it in a better position to endure the Martian winter — which just goes to show that a devil can be an angel on the Red Planet.
More from Mars:
- The Mars rover stays in the picture
- Watch a dust devil spin in the Martian arctic
- Slideshow: Greatest hits from the Red Planet
Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter or adding Cosmic Log's Google+ page to your circle. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for other worlds.
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I blame George Bush.
In Soviet Russia, George Bush blames YOU!
The sun doesn't seem to match the shadow. Looks like it's shining from both sides of it. Hmmm.
If the sun were coming from directly overhead, you'd be right. If the sun is coming from the horizon on the left, the shadow would be a function of the vertical plume, which this picture doesn't show.
What... you've never see a Tasmanian Devil before?
What... you've never see a Tasmanian Devil before?
oh my god! it's an alien!
That is a twister but the soil is dry and crappy. And it also means the cold air and hot air currents are mixed together. Where is hot air? Where is the cold air? The Mars has no stretosphere and has no ozone layer, hasn't it?
Some comments have been made about the difference in color between the dust devil's and the surface color.
To illustrate the (very) BASIC concept, here's a photo of some on earth:
http://www.stanford.edu/~thelero/images/photography/Dust%20Devils.jpg
There is also a pick-up truck driving across the field, kicking up a dust trail. Notice the difference in color from the (heavier) surface dirt, and the (lighter) dust, although both the dust and the dirt are made of the same stuff.
Also, not all of the stuff that makes up the martian soil is the same color. The reddish hue (iron-based componds) is predominate, but other things exist, and those particle-things are usually lighter in both weight (more finely ground) and color. This is probably why they (dust devils) leave a darker trail behind them as they travel ( Alen's APOD photo link )
Rember, I said Basically. I don't pretend to know everything.
There are other reasons and things, but PLEASE! ..., do some research. Finding out things for yourself, to your own satisfaction, instead of just asking others for the answers to questions, is much more fun!
How do you propose that the average person here on earth should go about investigating ANYTHING having to do with outer space, interplanetery travels, or other such wastes of time. We need to fix the planet we're on!
Well, obviously I wouldn't advocate that anyone spend time on anything they consider "... a waste of time.".
But for anyone that would wish to learn about these things, a good basic, high school level, foundation in the study of physics, math, chemistry and the other sciences is a good place to start. Reading introductory-level books on the various subjects that interest you is also a good way to get familier with the terms, facts and concepts used in those areas.
Anytime one starts a ladder of learning on any subject, the next rung in it usually presents itself.
Studying other planets, stars, galaxies, etc is a "waste of time"?? Un-freaking-believable!! People like you don't get it do you!? We take our knowledge of this planet and incorporate it into understanding other planets! In the process we also learn more about our planet! But hey, don't let facts such as these get in your way! In other words, try using your brain once in awhile, use the internet for something other than porn, and THINK!
The "average person" who's interested in "investigating" more about such things can further their education then get a job in a related field so they to can "investigate" the wonders of the universe. You sound as though you're pissed or jealous because you never (or ever will) get to go for a ride on a rocket ship. Get over it! But why ask the question of this is "such a waste of time"??
There are many MANY people trying to fix the problems we have on this planet! Perhaps by exploring other worlds we might find something that would help eleviate many of those problems! But, if you never look you'll never find ANYTHING!!
BoJap your on the mark. Anyone notice how the shadow does not match the cloud?
The shadow's not a shadow, it's just darker dirt on the ground under the twister. The lighter colored dirt was sucked up into the air, where it's getting twisted into a snaky shape.
The shadow does'nt MATCH
It is clearly Elvis riding a 4x4.
If you look closely, you can see his teeny tiny sequined space-suit
Probably because I am opposed to the government dumping such massive amounts of money into "space exploration" when that same money could be used more effectively here on earth, but to me that representation of a "dust devil" looks fake as hell; not even a good fake at that. Besides, who cares?
Well, you're wrong, and you're wrong again, and I do.