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Mars Polar Cap Mystery Solved

Posted by Soulskill on from the feather-in-their-cap dept.

Matt_dk writes "Scientists are now able to explain why Mars' residual southern ice cap is misplaced, thanks to data from ESA's Mars Express spacecraft (the same probe running the 'Mars Webcam'). It turns out the martian weather system is to blame. And so is the largest impact crater on Mars — even though it is nowhere near the south pole. Like Earth, Mars has frozen polar caps, but unlike Earth, these caps are made of carbon dioxide ice as well as water ice. During the southern hemisphere's summer, much of the ice cap sublimates, a process in which the ice turns straight back into gas, leaving behind what is known as the residual polar cap. The mystery was that while the winter cap is symmetrical about the south pole, the residual cap was offset, and scientists couldn't figure out why."

14 of 77 comments (clear)

  1. What do they mean 'misplaced'? by Tumbleweed · · Score: 4, Funny

    It's right where I left it.

    1. Re:What do they mean 'misplaced'? by morgan_greywolf · · Score: 5, Funny

      In the sofa cushions? That's where I usually find my keys. Did NASA find their keys, too? What about the TV remote?

      Yep. You should always look in the couch cushions. And under the couch. That's where I found Jesus.

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    2. Re:What do they mean 'misplaced'? by Anonymous Coward · · Score: 5, Funny

      Yep. You should always look in the couch cushions. And under the couch. That's where I found Jesus.

      You work for the Border Patrol or the Bureau of Immigration?

  2. The answer is simple by Weaselmancer · · Score: 5, Funny

    Mars did the calculation for one pole in Metric and the other one in Imperial. That's why they don't line up.

    Of all people, NASA should know this.

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    Weaselmancer
    rediculous.
  3. Alien planet by Dan+East · · Score: 4, Interesting

    It seems absurdly simple, but it is quite foreign to meteorology on our planet to have an impact crater affecting the global climate and weather patterns. That will be just another of those little things that will give future astronauts the "this isn't Kansas anymore" feeling as they live on another planet.

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    1. Re:Alien planet by mmalove · · Score: 5, Funny

      "It seems absurdly simple, but it is quite foreign to meteorology on our planet to have an impact crater affecting the global climate and weather patterns."

      Tell that to the dinosaurs...

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    2. Re:Alien planet by fizzup · · Score: 4, Funny

      Tell that to the dinosaurs...

      They aren't in Kansas anymore, either...

    3. Re:Alien planet by ianare · · Score: 4, Informative

      You seem to be confusing two different effects of a large asteroid impact - initial and long term.

      One of the initial effects will be a huge cloud of dust, blocking almost all sunlight for years at at time - this is what caused the mass extinction at the end of the cretaceous. Others include giant tsunamis (if it crashes into a liquid), 'rain' of molten rock and ash, earthquakes, ect ...
      However, on Earth, there are few long term effects, none of which include altering global weather patterns long term. This is due to our planet's ever-changing surface, with new land being created, land being destroyed, and of course continental drift. Mars has no active volcanism and no continental drift, therefore a surface feature which would be rapidly (in geological terms) altered on Earth would last for a very, very long time on Mars.

      Another thing is that we have a much thicker atmosphere, reducing the size of the asteroid before impact, AND the probability of it hitting solid ground as opposed to water is about 30/70.

  4. Marvin vindicated by UnknowingFool · · Score: 4, Funny

    In a press statement, Marvin the Martian's publicist told reporters that Marvin felt joy that hey was vindicated by the scientists' report. "Marvin has said all along that the missing polar cap had nothing to do with his lifestyle decision in owning 12 Hummers or related to his Illudium Pu-36 Explosive Space Modulator factory emissions." The publicist did answer allegations that the factory used illegal cartoon workers that were drawn and not colored. A spokesduck from the leading cartoon union said, "For cartoons to be drawn and not colored, that's dessssssspicable!"

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  5. The real reason is that... by KiwiCanuck · · Score: 5, Funny

    Mars prefers to where it's winter cap, gangsta style.

  6. Martian atmosphere by fprintf · · Score: 5, Insightful

    I don't know why, but I always though of Mars as a planet without an atmosphere. Perhaps like our Moon, just much bigger. So when first reading the article, I thought that as soon as the carbon dioxide gas sublimated, it would be lost to space.

    However, the atmosphere is just really thin: http://starryskies.com/solar_system/mars/martian_atmosphere.html

    So, thanks to Slashdot, I once again expand my knowledge of the universe and learned something new today!

    Maybe now the ending scene in Total Recall makes some more sense? I'll have to rewatch it and see...

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  7. Still not answered... by ivandavidoff · · Score: 5, Funny

    Is the angle of offset rakish or merely jaunty?

  8. Two mysteries linked by Rossby waves by exp(pi*sqrt(163)) · · Score: 5, Interesting

    The important phenomenon at work here is that of Rossby waves. It's interesting that this type of polar standing wave may also be implicated in the famous Saturnian hexagon.

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  9. Re:Carbondioxide-ice by morgan_greywolf · · Score: 5, Funny

    I heard that it's sublime!

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