Scientists say Mars has thousands of glaciers buried beneath its dusty surface, enough frozen water to blanket the planet with a 3.6-foot-thick (1.1-meter-thick) layer of ice. The glaciers are found in two bands in the mid-southern and mid-northern latitudes.
Radar readings from Mars orbiters were combined with computer models of ice flows to determine that the planet has about 5.3 trillion cubic feet (150 billion cubic meters) of water locked in the ice. That's according to a study published in this week’s issue of Geophysical Research Letters. The volume is roughly equal to the amount of water contained in Lake Tahoe on the Nevada-California border.
Scientists have been trying to figure out how Mars was transformed from a warm, wet and presumably Earth-like planet early in its history into the cold, dry world that exists today. Because Mars lacks a protective, global magnetic field, much of its atmosphere was stripped away billions of years ago. Today, "the atmospheric pressure on Mars is so low that water ice simply evaporates and becomes water vapor," the University of Copenhagen's Neils Bohr Institute said in a news release.
The researchers suspect that the Martian glaciers remained intact because they were protected under a thick layer of dust.
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The authors of the research paper, "Volume of Martian Mid-Latitude Glaciers From Radar Observations and Ice-Flow Modelling," include Nanna Bjørnholt Karlsson, L.S. Schmidt and C.S. Hvidberg.