Between the Devil and the deep Red Planet

By Phil Plait | March 7, 2012 10:45 am

Mars is a pretty incredible place. It’s way too easy to easy to think of it as a cold, dry, dead world, but that’s not really true: it has an atmosphere (though thin), it has seasons, and it even has weather.

Circling the Red Planet is the Mars Reconnaissance Orbiter, and with its HiRISE camera it has a fantastic view of the changing face of the planet. And it so happens that sometimes MRO is looking at just the right place, at just the right time, to capture astonishing events… like this magnificent twisting dust devil towering over the landscape:

Holy wow! [Click to barsoomenate.]

This picture is just amazing. Dust devils are wind vortices, like tornadoes, but generally not as violent. They form when sunlight warms the surface of Mars. The air just above it gets warmer and rises. If there is a crosswind, it can blow across the rising air and start it spinning like waves breaking on a beach. But since the air is rising, it can lift up vertically while still spinning, forming a dust devil.

I’ve seen them here on Earth all the time; driving across the American southwest one day I saw dozens, including one that was easily a hundred meters across. And so it happens on Mars too. But I’ve never seen one like this! Given the shadow and height of the Sun when this shot was taken, the devil must have been 800 meters high — a half a mile! That’s huge.

The dust devil actually was relatively vertical until a height of about 250 meters above the ground, where the wind caught it and swept it back into that serpentine shape. The path of the dust devil was actually fairly straight; it’s just the plume being whipped around that makes it look wavy (the shadow on the surface adds a wonderful depth to it as well).

Devils usually commonly leave behind interesting tracks on the ground as well as they sweep away dust, which can be phenomenally beautiful and intricate. That’s not easily apparent in this closeup, but I’ve included a shot here that shows a much larger area — you can see the dust devil at the bottom for scale — and there are bright tracks all over the place, where earlier devils have swept up surface material.

As the folks at HiRISE point out, it’s interesting that these tracks are bright and not dark as usual. The area seen here has thick dust that is too heavy to be picked up by the devil’s winds, but there is lighter dust scattered around on top of the thicker material. It’s likely that after the dust devil moves, the lighter, brighter material swirls and settles behind the vortex, forming those tracks.

Dust devils are most common in the spring, when atmospheric conditions are best for them, and it happens to be late spring in this location on Mars. And having seen dust devils like this on Earth — where they are mesmerizing and fascinating — I have to wonder. Will my descendants someday put on a pressure suit and protective gear, walk out an airlock into a rusty landscape and butterscotch sky, and see a phenomenon like this towering above them?

I hope so. I surely do.


Related Posts:

- The artwork of the Martian landscape
- Martian dunes under the microscope
- A tornado made of fire. Seriously.
- The devil is in the details

CATEGORIZED UNDER: Astronomy, Cool stuff, Pretty pictures
MORE ABOUT: dust devil, HiRISE, Mars, MRO

Comments (32)

Links to this Post

  1. ALL THE LINKS » L’esprit d’escalier | March 9, 2012
  1. Frank

    Dust devil? That’s clearly a giant Martian ghost-sperm. Do your research next time.

  2. Brent Hagany

    I hate to be that guy, but it should be descendants, not ancestors.

  3. Chris

    Ancestors or descendants? :P

  4. @Frank: you owe me one coupon for keyboard coffee removal.

  5. ironnmetal

    I think you meant descendants in your last paragraph, but still an awesome article! I think a lot of people have this misconception about the other planets, that they’re so vastly different from Earth and that there’s nothing to relate to.

  6. Iain Brown

    It’s not a long hop from Barsoom to H.G. Wells, maybe Phil’s descendents are also his ancestors!

  7. yarb

    Super photo, thanks! But what freak of spacetime are you counting on to put your ancestors on Mars? ;)

  8. Scott

    How freaking awesome is it that we can actually photograph *weather* on Mars!

  9. ceramicfundamentalist

    can someone remind me why we’re not going to mars? there are so many things there i want to see and do.

  10. Ryan

    Your descendants, I think you meant to write, rather than your ancestors. Unless there’s a time travel subtext I failed to pick up on.

  11. Frank

    ceramicfundamentalist: Have you tried going to Mars? Turns out it’s really hard.

  12. Old Muley

    Looks like some martian is letting the campfire get out of hand…

  13. Cathy

    I always figured that folks from Georgia or the South in general are good candidates for Mars colonization. The red sky will be weird, but we’re very much unfazed by bright red dirt.

  14. cynthia

    Um someones mind is in the gutter lmao @ Frank

  15. eyesoars

    Some of us use these things for recreation.

    Here on earth, these things not rarely reach altitudes of over two miles, diameters of up to a half-mile, and will happily carry suitable vehicles along with them. I’ve used them to travel over 300km several times, reached altitudes of 17,999′ (and upwards vertical speeds over 30km/h), and spent more than five hours aloft many times.

    And Boulder is a pretty good place for this.

    (I should perhaps point out that it doesn’t seem to take a breeze to make these things spin; they seem to do it naturally and often spin much faster than the prevailing breezes.)

    /es
    (Happy pilot of a motorless, fusion-powered, alien built singleship.)

  16. ragnar

    Speaking of Mars, I would like to remind everyone that on Friday (9 March) the documentary about John Carter’s trip to Mars will be in theaters.

  17. Speaking of dust devils, didn’t one of the rovers take advantage of a dust devil to clean of its solar panels one time? That was some cool use of weather.

  18. CR

    Larian (@17), yes that did occur at least once.
    I also recall (on this very blog, if memory serves) seeing ‘video’ of dust devils in motion using pics from one of the rovers. It was actually a series of stills stitched together to make a crude animation… now that I think about it, said video might have been of clouds moving across the Martian sky, but I swear that there was also a dust devil ‘video’ in addition to the cloudscape one. Anyone else who’s been a reader here for at least a few years remember those?
    (comes back to edit after following links and looking around…)
    Oh, it”s the “The devil is in the details” entry, and it looks like back then I had made the first comment. No wonder I thought it was on this very blog! (Duh…)

  19. Georg

    “”They form when sunlight warms the surface of Mars. The air just above it gets warmer and rises. If there is a crosswind, it can blow across the rising air and start it spinning like waves breaking on a beach”"

    This is not the way such a devil is made. Crosswinds have to be low,
    in order to give enough hot air above the surface the possiblility to accumulate.
    After that the process goes on as it does for a twister or a cyclone on a much
    bigger scale.
    Georg

  20. Messier Tidy Upper

    @13. Cathy – March 7th, 2012 at 11:50 am wrote :

    I always figured that folks from Georgia or the South in general are good candidates for Mars colonization. The red sky will be weird, but we’re very much unfazed by bright red dirt.

    Sounds like much of the Aussie outback with its red gibber plains and red sands – especially the northern and western deserts of my own state of South Oz. This Aussie for one, would love to go visit Mars! :-)

    @12. Old Muley – March 7th, 2012 at 11:39 am wrote : “Looks like some martian is letting the campfire get out of hand…”

    It sure is white like smoke but as you probably already know with the oxygen bound tothe rust-red rocks there can be no combustion fires on Mars :

    “There were no fires in the Martian desert. In fact, of all the worlds in the solar system only Earth with its oxygen-rich atmosphere knew fire.”
    - Page 43, ‘Voyage’, Stephen Baxter, Harper-Collins, 1996.

    @11. Frank – March 7th, 2012 at 11:35 am wrote :

    ceramicfundamentalist: Have you tried going to Mars? Turns out it’s really hard.

    Remeber what JFK said? “We do these things NOT because they are easy but because they are hard.” The hardest things are often the most worthwhile and remarkable to achieve. We learn so much and gain so much by striving and adventuring and heading out beyond the next hill, next ocean, next planet. Its a vital part of what makes us Human. As one SF writer – I forget exactly who now – once noted, the meek may inherit the earth but the bold will have the stars! ;-)

    Yes, human travel to Mars will be an incredibly difficult dream to accomplish. So was flying to the Moon, so was flying at all before the efforts of the earliest aviators got us airborne. So was European exploration and colonisation of the world with sailing ships back in the days of Captain Cook, Sir Francis Drake and Ferdinand Magellan.

    Are we less capable, less bold, less visionary than our ancestors? Will we do a China post Admiral Cheng Ho (or is that Zheng He or something like that – spelling? You know the one I mean I hope.) and start to explore and advance only to give up, burn our boats, stagnate and have our civilisation toppled by those who are more daring and willing to advance however hard it is?

  21. Messier Tidy Upper

    .. having seen dust devils like this on Earth — where they are mesmerizing and fascinating — I have to wonder. Will my descendants someday put on a pressure suit and protective gear, walk out an airlock into a rusty landscape and butterscotch sky, and see a phenomenon like this towering above them? I hope so. I surely do.

    Very well said, Phil – me too. :-)

    I always thought as a young kid growing up that I’d see this happen in my own lifetime but over recent years I ‘m fearing this won’t be so no thanks at all to Obama and the presidents before him – and their visionless myopic bean-counters – back to JFK who have failed to capitalise on and advance human space exploration beyond the limits it reached in the early 1970′s with the Apollo Moon landings. :-(

    I also hope that one day our descendents – or the way we’re trending maybe more likely the Chinese or Indian people’s descendents will take Mars as it is now as a starting point and work towards terraforming it along the lines of Kim Stanley Robinson’s Mars trilogy – among others. I think Humanity can and hopefully will bring life to Mars and other worlds and create wonders and remarkable, gloriously good places and homes out there in the Black.

    I’m disappointed with what we’ve done or rather not done over past few decades, but, yes, I’m still a dreamer and largely optimistic longer term when it comes to the future for our species. :-)

  22. Searle

    this might not be the most interesting thought, but it’s free and might only interest me:
    this reminds me of that ‘Mission to Mars’ movie. It’s not a terrible movie. There is a scene where astronauts get caught up in some type of dust devil wind pattern. It ends badly for them. But the movie of course makes it that the dust storm is alien controlled. Wonder if I can find the scene on youtube. oh wait, Bad Astronomy dude reviewed the movie in 2011.

  23. Searle

    storm in ‘Mission to Mars’ (music has been changed from original)

    http://www.youtube.com/watch?v=QwrrlQ2SRu0#t=3m03s

  24. vince charles

    20. Messier Tidy Upper Said:
    March 7th, 2012 at 5:05 pm

    “Remeber what JFK said? “We do these things NOT because they are easy but because they are hard.” ”

    Gee, that, and the fact that the Department of Defense (via the Army, of all orgs) was planning on Moon missions before Kennedy set one foot in office. The Air Force, Navy, _and_ Army all had space vehicles before Kennedy; the Shuttle only cut metal with Air Force backing.

    Meanwhile, the Department of Defense has, to my knowledge, identified no technologies from Manned Mars that: 1) enhance its Earth- or Near-Earth activities, and 2) are not already in some stage of development or operations.

    Burning boats, indeed. For the umpteenth time, please stop posting at length how you think you know how a successful initiative works, let alone our initiatives.

  25. Nigel Depledge

    Scott (8) said:

    How freaking awesome is it that we can actually photograph *weather* on Mars!

    11.

    That’s how freakin’ awesome.

  26. Nigel Depledge

    Frank (11) said:

    ceramicfundamentalist: Have you tried going to Mars? Turns out it’s really hard.

    And very expensive (with current technology).

  27. ceramicfundamentalist

    wow, so many defeatist responses to my post…

  28. A new book by astrophysicist and Hayden Planetarium Director Neil deGrasse Tyson makes a strong case for why the United States needs to invest in space again. He makes compelling economic, scientific, and cultural arguments for reinvigorating our space program. The book is “Space Chronicles: Facing the Ultimate Frontier.”

    http://www.amazon.com/Space-Chronicles-Facing-Ultimate-Frontier/product-reviews/0393082105/ref=cm_cr_dp_all_helpful?ie=UTF8&showViewpoints=1&sortBy=bySubmissionDateDescending

    NPR’s Science Friday host Ira Flatow interviewed Neil about the book on March 4th. The interview is posted on the Science Friday website at

    http://www.sciencefriday.com/program/archives/201203024 .

  29. eyesoars

    Georg@19:

    Winds on the surface don’t have to be as low as you might think. Although lower-areas like stream-beds and similar sheltered areas do help significantly and often kick them off, they do occur with ground-level winds up to 25 knots or more. (It is probably true that they are less likely to carry visible dust with them under such conditions, and they tend to be much more broken up.)

    Under windy conditions, they do tend to move with the breeze, however. On days with less wind, you can sometimes see the warm layer of air on the ground converging towards the dust devil, especially if, e.g., there is a farmer pulling a plow or some other source kicking up a lot of dust at ground level. If there are multiple flags or wind-socks around, you can also infer their existence by the flags or wind-socks pointing at it as it moves through (when there’s no dust to show it).

    They can also have non-trivial internal structure: I’ve seen them split a few hundred feet off the ground into a Y shape, with one cylinder on the ground, and two five hundred feet up.

    On Earth, they often rise rise until they’ve cooled (adiabatically) enough to condense into a cloud. Other processes may kick in then, especially if the top of the cloud is below the freezing point of water; ‘cloud suck’ beneath a cloud can reach 60 knots or more. Usually right before it becomes a thunderhead.

  30. Nigel Depledge

    Ceramicfundamentalist (27) said:

    wow, so many defeatist responses to my post…

    It’s not defeatist to recognise that, in the current economic climate, NASA simply won’t get the funding necessary to assemble a halfway sensible Mars programme.

    AFAICT, all of the challenges inherent in a mission to Mars can be overcome as long as the budget is big enough. What I don’t see is Congress voting that big a budget to NASA for the length of time needed to develop all the required hardware and procedures.

    You could, of course, argue that the Chinese might get there first, but I’m not aware of any source of information about the Chinese space agency that would allow us to make a judgement one way or the other.

  31. HumeBastich

    so thats what killed the Martians!! SOMEONE GO GET COMMANDER SHEPHARD!!

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