Water on Mars

By Sean Carroll | August 4, 2011 12:13 pm

Here’s a pretty picture from JPL, based on data from NASA’s Mars Reconnaissance Orbiter. Click to see a larger version. (Note that the image is highly doctored, in the best NASA tradition; not just false-color, but they’ve “reprojected” so that a satellite image now looks like it was taken by a flying helicopter!)

Water on Mars” is one of those things (like “black holes” or “the missing link”) that seems to be discovered over and over again. That’s because we’re not really finally discovering it once and for all; we’re slowly gathering new evidence, and also evidence for different manifestations. It seems clear that frozen water exists in the polar regions of Mars; also, there’s good reason to think that there used to be running water at some point. This new finding would be evidence for running water right now.

In this case, NASA scientists have noticed seasonal changes in hillside patterns such as this one. The dark streaks seen in the image appear in the spring and summer, then fade again in winter. (Kind of like the Los Angels River, but backwards.) The best idea we have for an explanation is running water. Not that the darkness is water itself, but some change in the underlying substance as a result of water. It’s a very good idea — likely true — but still not quite like we’ve filled up a cup and done a chemical analysis.

Anything with any tenuous connection to “life on other planets” runs the risk that everyone wants it to exist and is looking very hard; consequently, skepticism is always warranted. Still: awesome pictures!

CATEGORIZED UNDER: Science, Space, Top Posts
  • Ellipsis

    Anything with any tenuous connection to “life on other planets” runs the risk that everyone wants it to exist and is looking very hard; consequently, skepticism is always warranted.

    Exactly — I have not been impressed with NASA’s complete lack of attempts to remain scientifically unbiased with regard to results of new studies in this area. (And I still remember NASA’s supposed discovery of “microbial life on Mars” approximately 10 years ago.)

  • Low Math, Meekly Interacting

    I feel a bit cautious myself after the “arsenate-based life” thing.

    Still, those dark streaks have to be due to something, something we obviously don’t fully understand, and are therefore intrinsically interesting regardless of their ultimate explanation.

    I’m not sure how impressed by life on Mars I’ll be, even if found. Really depends. Bacteria of some sort might just have been stowaways on Earthly ejecta. It would certainly be more intriguing if life actually travelled the other way. Both would be remarkable discoveries. But they wouldn’t be nearly as momentous as conclusive evidence of the independent emergence of life on another planet.

  • Mike Franklin

    I don’t buy it. There’s no reason to think that water exists anywhere else in the universe. All this stuff is just another attempt by the tin foil hatters to invent Martians.

    Where’s Shermer when you need him…

  • panini

    And to think that a manned mission could perform all the necessary analyses in what, one day?

  • http://voyagesextraordinaires.blogspot.com Cory Gross

    @4, panini,

    Yeah, but who wants to spend two years in coach? A flight to Japan nearly killed me.

  • Gadiel Tavarez

    Phil, this post is showing unformatted in google reader.

  • AI

    Please, seasonal changes in hillside patterns =/= water.

    This is would be entirely unconvincing even if the patterns actually resembled ones caused by flowing water but they clearly don’t. Its probably some dark rock material released due to erosion and deposited on brighter dust (or the other way around dust over rock material). The changes can be simply due to seasonal winds blowing the dust in/out.

  • Pingback: Hawking is an atheist « Why Evolution Is True()

  • http://NoplanetlikeTheEarth mimili

    Everybody has to know that there will be no planete like our planete, The Eeath!!
    Everything is made perfectly:-) You know that if we were closer to the sun we would have been able to burn and if we were farther we would have been able to freeze. The oxygen is also at the perfect level that we can breath.
    GOD is the creator of everything and if you believe in his son JESUS you will have eternel life.(in the bible John 3.16).

  • hi

    cherry is ugly

  • mimili

    I believe in life 100% on other planets, although I do believe in god, and if God made all these planets, why did he make out of them all earth so special, please ignore my other comment, I was really tired and as much as I do believe in life on other planets, definately not mars.

  • http://www.fassrolle.de/ Kathleen Siegert

    Flying eggbeater seems to be not elementary – plane aeronauts hold a high honor for it. Besides in the cosmos of modeltoys this is the supreme subject. But I think, with adequate good nature and dedicitaion almost everybody is be up to move a whirlybird or r/c helicopter.


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About Sean Carroll

Sean Carroll is a Senior Research Associate in the Department of Physics at the California Institute of Technology. His research interests include theoretical aspects of cosmology, field theory, and gravitation. His most recent book is The Particle at the End of the Universe, about the Large Hadron Collider and the search for the Higgs boson. Here are some of his favorite blog posts, home page, and email: carroll [at] cosmicvariance.com .


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