More details emerge of water ice on Mars

via Astronomy Now, Universe Today, Skymania, Discovery.

Credit: NASA/JPL-Caltech/University of Arizona

Credit: NASA/JPL-Caltech/University of Arizona

Last year there was a flurry of stories of water ice detected in subsurface layers over quite a bit of the surface. The Mars Reconnaissance Orbiter spotted glaciers in the southern hemisphere at latitudes of 30-60 degrees. Later detections of ice in fresh craters led to the suspicion that a similar layer extended beneath a widespread area. The Phoenix lander also saw a few possible drops condense on its leg, adding to suspicions of atmospheric vapour.

Credit: NASA/JPL-Caltech/Malin Space Science Systems

Credit: NASA/JPL-Caltech/Malin Space Science Systems

Now the mapping of the ice is complete, showing a layer extending halfway between the poles and the equator. So far that had NASA’s Viking 2 probe dug just ten centimetres deeper than it did into the soil of Mars (launched in September 1975), it would’ve encountered the ice. The layer is around a metre thick, up to ten metres and in some places down to a centimetre. It is believed to be a relic of wetter times on the red planet.

Credit: NASA/JPL-Caltech/University of Arizona

Credit: NASA/JPL-Caltech/University of Arizona

An astonishing find from observations of fresh craters was the purity of the ice thrown up by the impacts. It was believed the layers represented 50:50 mixes of ice and dust, however the stuff thrown out was 99 percent ice, 1 percent dust.

Credit: NASA/JPL-Caltech/University of Arizona

Credit: NASA/JPL-Caltech/University of Arizona

Once the ice was thrown up, it sublimated (turned directly to steam) in a couple of hundred days. MRO was able to use the time to point a spectrometer at it and confirm what it was. NASA’s press release on the subject is here and images are here.

Credit: NASA/JPL/University of Arizona

Credit: NASA/JPL/University of Arizona

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One response to “More details emerge of water ice on Mars

  1. Very well put together set of photo’s and information.

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