Evidence For Liquid Water On a Frozen Early Mars

Matt_dk writes "NASA scientists modeled freezing conditions on Mars to test whether liquid water could have been present to form the surface features of the Martian landscape. Evidence suggests flowing water formed the rivers and gullies on the Mars surface, even though surface temperatures were below freezing. Dissolved minerals in liquid water may be the reason."

Comments

Re:Whatever happened to...

[Yvanhoe]

Still valid, but this is not the question. They are trying to determine wether big bodies of water existed on Mars. About Mars having huge quantities of water ice, we know it from several years, we even have pictures of it and even a map of Mars' aquifers.

Early Mars was warmer [Re:Warmer?]

[Geoffrey.landis]

Is it possible that mars was warmer at a time? Either with a high level of CO2 or some other greenhouse gas that would have warmed the surface enough for running water?

Yes, that's a good summary of the current scientific thinking. The Viking orbital images show a lot of the surface is sculpted by water-carved features, and the belief is that Mars originally has a much thicker carbon dioxide atmosphere, which provided a significant amount of greenhouse warming (*). With the loss of Mars' magnetic field, this thick atmosphere was slowly eroded away by the solar wind to the very thin atmosphere we see today.

Maybe a little more dramatic but maybe even a slightly closer orbit?

No, that's quite unlikely. Planets are hard to move.

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*Footnote: The media likes to pretend that there is some controversy about the fact that carbon dioxide produces greenhouse effect warming (because controversy sells newspapers), but in the science community studying planetary atmosphere, there is no controversy whatsoever. It is just physics.

If you search hard enough, you can find somebody who disagrees, and quote them, and say, "look, not all scientists agree!" And since this is /. I'm sure somebody's about to do that: the miracle of the internet is that these fringe thinkers have just as loud a voice as people who have actually stufied the subject. But nevertheless, the greenhouse effect is just physics. And relatively simple physics.