Mars Rover Turns Up Evidence Of Water

New submitter horselight writes "Recent data obtained from Mars indicates the environment is not as hostile to life as once thought. 'An examination of data gathered by NASA's Mars Exploration Rover Opportunity reveals deposits that, on Earth, are only created by water moving through the rock.' The study's lead author, Steve Squyres, said, 'From landing until just before reaching the Endeavour rim, Opportunity was driving over sandstone made of sulfate grains that had been deposited by water and later blown around by the wind. These gypsum veins tell us about water that flowed through the rocks at this exact spot. It's the strongest evidence for water that we've ever seen with Opportunity.' Gypsum veins and other features indicating water movement on the surface of Mars have been observed to be much more common than previously thought."

Comments

Re:Haven't we seen this before?

[Tirian]

The working theory is that the lack of a strong magentosphere on Mars has allowed the solar wind to cause much of the water that was once present to be lost to space.

--Michael

Re:Water appearing on the surface is not the same.

[bgarcia]

At the poles it is not much of a toss. It is pretty safe to say that if there is water at the poles it is frozen and not very likely to turn liquid at any given time.

In Mars' low-pressure atmosphere, water will behave much like dry ice does on Earth - it converts straight between a solid and a gas without entering a liquid phase.

Phase Diagram of Water

Note that the air pressure averages around 600 pascals. That's below the solid-liquid-gas triple-point in the diagram. And temperatures on Mars tend to be well below the freezing point as well.