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Mars Space Science

Whirlwinds on Mars, From the Ground 122

Posted by timothy from the close-up dept.
Neil Halelamien writes "Back in 1999, satellite images were photographed of 5-mile-high whirlwinds streaking across the surface of Mars. A couple of months ago the Spirit rover got a close up view of whirlwind tracks, and this past week photographed a whirlwind in action (animation). It's thought that these dust devils may be responsible for the mystery power boost to the rovers' solar cells. Last year the rovers also spotted clouds and frost."
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Whirlwinds on Mars, From the Ground More

Whirlwinds on Mars, From the Ground

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  • Animation (Score:5, Informative)

    by FTL ( 112112 ) * <slashdot@neil.frase[ ]ame ['r.n' in gap]> on Saturday March 12, 2005 @08:01PM (#11922868) Homepage
    Incase you are wondering about the /.ed animation, it is a two-frame, black and white, 1MB gif. The first frame shows a small whirlwind in the distance, the second frame doesn't show the whirlwind.

    Not impressive compared to the tornado footage we're used to from the local TV station. But one must remember that the rovers' actions are scripted in advance. So it was a complete coincidence that a whirlwind happened to be in-frame when they took a photo. Which says something about how common they must be if we just happened to snag a picture of one.

    If you are still interested, here's a mirror [digitalroutes.co.uk].

    • Re:Animation (Score:3, Interesting)

      by drinkypoo ( 153816 )
      Actually, it won't tell us anything about how common they are until they snag a picture of another one :)

      • Re:Animation (Score:5, Informative)

        by Zone-MR ( 631588 ) * <slashdot AT zone-mr DOT net> on Saturday March 12, 2005 @08:21PM (#11922962) Homepage
        it won't tell us anything about how common they are until they snag a picture of another one

        Yeah it does. We can assume that a tornado is visible 1/Nth of the time, where N is the total number of pictures taken by the rover, and the 1 represents the picture with the tornado visible.

        If the rover snags a picture of another tornado it will increase the accuracy of our prediction slightly.

        • Re:Animation (Score:5, Insightful)

          by Surazal ( 729 ) on Saturday March 12, 2005 @08:44PM (#11923067) Homepage Journal
          If the rover snags a picture of another tornado it will increase the accuracy of our prediction slightly.

          If it doesn't find another tornado, then that also will increase the accuracy of the prediction slightly. ;)

        • Re:Animation (Score:3, Informative)

          by drinkypoo ( 153816 )
          That is way way way too simple. You have to take into consideration the field of view, the amount of movement, the frequency of the pictures, the speed of the phenomenon, and the relatively short time in Mars' period that we have had rovers there :P For all we know there's ten times as many (or ten times fewer) tornadoes in other parts of Mars, due to terrain features...

      • Re:Animation (Score:2, Interesting)

        by Tablizer ( 95088 )
        Actually, it won't tell us anything about how common they are until they snag a picture of another one :)

        They can count the darkened dust trails from orbit. In fact, they caught some in progress from orbit. You see a dark trail that ends in a whitish puff IIRC. If they monitor an area from orbit over months or years, they can get a better estimate of the change rate. Plus, if it was a dust devil that cleaned the panels, that is another "hit". And, Pathfinder imaged one also.
    • Thanks for the mirror :)

    • Re:Animation (Score:5, Funny)

      by CrackedButter ( 646746 ) on Saturday March 12, 2005 @08:14PM (#11922930) Homepage Journal
      Looks more like a ghost to be honest. The ghost of Beagle WOOOOOOOO....
      • The freaky thing is that this comes one day after "Mission to Mars" came on local TV. Hmmmm... Perhaps it's a sign that Germany has joined the Deep Space Lie program (you know, the one that tries to make uns believe that there are other planets beside Earth). I better go get my tin foil helmet.

    • Re:Animation (Score:5, Insightful)

      by tverbeek ( 457094 ) on Saturday March 12, 2005 @08:20PM (#11922960) Homepage
      Calling it an "animation" is stretching it pretty far. The second frame isn't even on-register with the first one, so it's really just a pair of "with" and "without" snapshots.
      • heh, that animation sucks! [tvtome.com]
      • Calling it an "animation" is stretching it pretty far.

        Further, they did not need to use the entire frame for each. That makes it too long to download. Just have say 200 x 200 pixel's worth.

        (I suppose beggars shouldn't be choosers. It's not like we paid for it, and we can make our own if we don't like their's. Open source animation philos.)

      • Re:Animation (Score:3, Informative)

        by QuantumFTL ( 197300 ) *
        Calling it an "animation" is stretching it pretty far. The second frame isn't even on-register with the first one, so it's really just a pair of "with" and "without" snapshots.

        I used to work on MER, and I discussed this issue with Daniel Crotty (the man who made the animation featured here), and it was decided that:
        1. Good coregistration was too difficult with the available information. I've written coregistration code before, for the CAHV [uni-hannover.de] linearized images, however there are serious problems when usin
        • As for it not being an animation... how many frames do you need for something to be an animation?

          You need enough frames to produce the visual illusion of motion. The bare minimum is two frames of the "moving" object. But this sequence includes only one frame of the whirlwind, then another frame in which it's absent, and the illusion of movement simply doesn't happen. What we get instead is the illusion of disappearance. The only objects that actually appear to move in this sequence are the rocks (due

      • Yeah, sorry, sorry. When I used the term "animation" in the submission, I was mostly referring to the fact that it was an animated GIF, albeit a 2-frame one. In retrospect, something like "slideshow" may have been a better choice of term.

        My apologies.

  • For the hardcore: (Score:5, Interesting)

    by hot_Karls_bad_cavern ( 759797 ) on Saturday March 12, 2005 @08:04PM (#11922888) Journal
    "Now we're assuming they're cleaning, but all we can really say is that overnight the solar panels produced between 2 and 5 percent additional power immediately,'' he said. "We're surmising that for some reason dust is being removed from the solar panel and that's increasing the efficiency of the sunlight being converted to electricity."

    Any hardcore space-geeks care to propose any other explanation?

    Seriously, i'm just wondering what else might explain this, because enough moving atmosphere on Mars to clean the panels is very interesting to me. Other possibilities anyone?
    • Vibration from movement: is there enough jostle to shake dust off the panels from mere rover movement about the surface or is that too small to matter here?

    • Re:For the hardcore: (Score:5, Interesting)

      by Quiet_Desperation ( 858215 ) on Saturday March 12, 2005 @08:09PM (#11922905)
      Motion of the rovers? I would imagine the lower moisture levels (if any) would make the dust there less sticky. I'd be curious to know if the rovers went through any serious inclines just bfore the power boost. Or if there was any unusually extensie activity of the probe arm and/or drill.
      • Motion of the rovers? I would imagine the lower moisture levels (if any) would make the dust there less sticky

        While that is certainly true to some extent, extremely dry air, like that found on mars, allows large static electric charges to build up (especially considering how close the atmosphere is to vaccuum). MER scientists speculate that a lot of dust buildup is caused by electrostatic attraction (I have even heard this in regards to the wheels, but am unsure how well verified that claim is).

        On the

    • Re:For the hardcore: (Score:3, Interesting)

      by ckemp.org ( 667117 )
      One thing confuses me, too: when the wind picks up on Mars, it turns into a dust storm, which I'm assuming dumps dust on the solar panels. Why would the whirlwind not pick up dust as well and deposit it on the panels? The twister in the picture seems relatively clear, consisting the red dust of the planet.
      • Perhaps there is very little lifting power in the wind, and all that air is simply spinning around. That way it wouldn't pickup that much dust from the ground and could have pushed away the dust on Spirits panels rather than sucking it up.
    • Something is eating the dust?

    • Re:For the hardcore: (Score:3, Interesting)

      by sydres ( 656690 )
      perhaps it has something to do with static charges maybe the rover comes into contact with a bit of ionized particles wich drains the neutralizes the static charge on the rover
      • hmm..
        I imagine that the rover would generate some static charge as it moves along (like rubbing your feet on a carpet).

        The dust devil would also generate static as the duct particles or dust collide.

        So there's a tiny chance that static played a part, but I should imagine that if there's enough wind to generate a dust devil then there's enough wind to blow a bit of dust off of the solar panels, not much of a mystery really.

    • Re:For the hardcore: (Score:1, Interesting)

      by Anonymous Coward
      it probably was the dust devil. I am a student at Cornell U. where the rovers are controlled, and my astro prof (the guy in charge of the rovers) said last week they hoped to see a dust devil and that it would clean off the panels... quite a coincidence that it happened so soon after he told us...
    • The air pressure could have dropped enough to cause the dust to evaporate, a dust devil is a sign of low air pressure.

      Though this is about as probable as a bugs bunny cleaning the panels with his tail whilst chasing marvin.
    • It is quite obvious [img138.exs.cx] at this point that this is in fact what has happened [img162.exs.cx]. Often the simplest explanation really is the most correct! I submitted an article yesterday but... :o( oh well. It's said that the rover has increased its power output from ~350 Watt/hr. to over 700+ Watt/Hr!! It's nearly like a new mission! :)
    • I don't know how much credence the idea has right now, but the original guess I heard from JPL was it was water vapor was causing the dust to clump as it condensed, froze and expanded, then melted and evaporated or else sublimated. Of course, they took pictures of the solar panels on Opportunity and didn't see any clumps, so if they existed, the clumped dust must have been more susceptible to being blown off in a gentle breeze. They have, however, taken several pictures of frost on the rovers.
    • Comment removed based on user account deletion

  • Dear God! (Score:3, Funny)

    by Pan T. Hose ( 707794 ) on Saturday March 12, 2005 @08:05PM (#11922892) Homepage Journal
    Have you followed the animation link? There is something at the bottom that looks like a tiny tinfoil hat that appears and disappears and reappears ad nauseam! Just thinking about it I have whirlwinds in my head... I need to get some sleep.

  • Noooo (Score:2, Funny)

    by Anonymous Coward
    It's thought that these dust devils may be responsible for the mystery power boost to the rovers' solar cells.

    It was Martians who powered them up!! This dust devil theory is just yet another government trick in fooling you that there are no Martians!! Next they'll reiterate there's no giant face sculpture on Mars. :(

    • Re:Noooo (Score:3, Funny)

      by the_weasel ( 323320 )
      No, we just replaced the batteries. I have to get back to the set now, one of the rovers needs to be prepped for the next shot. We are taping the discovery of a new form of sand ridge, and I need to load the film.

    • Next they'll reiterate there's no giant face sculpture on Mars. :(

      Actually, there is no giant face sculpture. They pulled it down to make place for a mall.

    • Re:Noooo (Score:2, Funny)

      by NaCl ( 414038 )
      there's no giant face sculpture on Mars. :(

      It's more like :-|
  • Would these areas be good places for future missions because of this? I mean, if we knew with a good amount of certainty that there will be storms which will clean off solar panels, this could be a target area for future long term missions?
    • ...was chasing after storms a good idea? There are far less risky ways of getting solar panels cleaned. Like wiper blades, air jets or sets of traffic lights. ;-)
    • It doesn't seem like a good thing to count on. In Spirit's case, it was over 400 days into the mission before it got this boost. They've been dealing with decreased energy availability for months. Plus, they estimated the odds were about equally as likely that some other critical part of the rover would fail before the solar panels became obscured. They will, however, probably reconsider their estimates for how long a solar powered rover can operate. The Sojourner lasted about 90 days, so they figured with
    • How about friggin windshield wipers? I bet the energy it would take to run a cleaning cycle on the solar panel would be worth the extra longevity.

  • Windsock (Score:5, Interesting)

    by Ohreally_factor ( 593551 ) on Saturday March 12, 2005 @08:10PM (#11922909) Journal
    Will the next batch of rovers be equipped with windsocks, to measure the direction of the wind?

    And what do you call those spinning things to measure airspeed? The ones with four arms with little hemispheric "cups" that catch the wind. KnowwhatImeanVerne?
    • And what do you call those spinning things to measure airspeed? The ones with four arms with little hemispheric "cups" that catch the wind. KnowwhatImeanVerne?

      A Science Vessel [battle.net]?

    • Re:Windsock (Score:3, Informative)

      by FrostedWheat ( 172733 )
      Pathfinder had something I liked to call the wind chimes. They didn't move about much, I'm guessing because that lander was so close to the ground and the landscape was quite rocky.

      Here's an animation here [nasa.gov] and some info.
    • Will the next batch of rovers be equipped with windsocks, to measure the direction of the wind?

      Pathfinder had windsocks. [nasa.gov]

    • Re:Windsock (Score:5, Funny)

      by tverbeek ( 457094 ) on Saturday March 12, 2005 @08:42PM (#11923047) Homepage
      Will the next batch of rovers be equipped with windsocks,

      I'm just hoping they'll be equipped with a Winsock, so they can run nifty TCP/IP apps like Mosaic and WS-FTP, and maybe even a web server like ZBServer!

    • And what do you call those spinning things to measure airspeed? The ones with four arms with little hemispheric "cups" that catch the wind.

      Personally, I go with "rotating bras on a stick"
    • the spinning cups thing for measuring wind speed is called an anemometer.
    • Will the next batch of rovers be equipped with windsocks, to measure the direction of the wind? And what do you call those spinning things to measure airspeed?

      They are called anemometers [wikipedia.org]. Some of the less advanced models do use spinning cups, however this can interfere with the wind flow you are studying (especially for small phenomenon length scales) and only works for two dimensions. There is another type, called an Acoustic Anemometer [ferret.com.au] (don't be afraid to click on ferret.com.au :)) that uses sound a
    • And what do you call those spinning things to measure airspeed? The ones with four arms with little hemispheric "cups" that catch the wind. KnowwhatImeanVerne?

      If only you had played the Space Quest series as a kid....

  • Spirit power boost (Score:5, Insightful)

    by FrostedWheat ( 172733 ) on Saturday March 12, 2005 @08:14PM (#11922927)
    The link talks about Opportunity's power boost, but a few days ago Spirit also had the same thing happen to it [space.com].
    Quite amazing stuff, if this keeps up the rovers should last a very long time!
  • Pretty cool idea, but this image seems to be a major let down. I understand there is limited data/photos but its almost better to just not have something than have this.

    Also -- and I realize this is a bit offtopic, but this clearly does not work for me in Firefox. I get one frame and a flash of the second, not enough to see it clearly.

    Works fine in IE.

  • Who made the dust devils? (Score:3, Funny)

    by Anonymous Coward on Saturday March 12, 2005 @08:24PM (#11922974)
    It's easy TAS the devil is on holiday, got a ride with duck dodgers and presto, thats why they are called dust "devils"

  • frost already observed in 1979 by Viking (Score:3, Informative)

    by idlake ( 850372 ) on Saturday March 12, 2005 @09:42PM (#11923382)
    Frost on Mars had already been observed by Viking in 1979 (e.g., here [habitablezone.com]).
  • It looks to me like the surface is covered with little whirlwind tracks. Do whirlwinds explain why there are so many lighter patches in the pictures from the animation?

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