Ice geysers found on Mars
Artist's impression of ice geysers on Mars
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Monday, 21, Aug 2006 12:41
Scientists believe that they have identified ice geysers in the south polar ice cap on the planet Mars.
Writing in the journal Nature, Hugh Kieffer, Philip Christensen and Timothy Titus of Arizona State University outline their study of infrared images of dark spots, fans and blotches which form as the south polar seasonal carbon dioxide ice cap retreats during spring and summer.
Previous studies suggested that the dark marks on imaging systems were areas of defrosting ice which exposed the soil underneath, but the researchers believe that the temperatures of the spots are too cold to be on the surface.
As the spots and fans remain at carbon dioxide ice temperatures during the summer months, the scientists believe that they must be granular materials that have been brought to the surface of the ice by a complex process.
This process, they argue, is due to a high pressure of gas which forms under the slab of carbon dioxide ice and eventually ruptures - creating high velocity vents, or 'ice geysers', which form the spots.
"The formation of translucent slab ice,...high-velocity carbon dioxide gas jetting, and eruptions of sand are unlike any phenomena observed on Earth," the authors write.
They conclude that their findings could have major complications for records related to the sedimentary layers on Mars and its climate history.