New research shows Mars' buried glaciers contain enough ice to cover the entire planet with a coat three feet thick. The evidence also proves the dust-covered glacial belts to contain frozen water, not carbon dioxide.

Previous satellite images have suggested the presence of hefty glacial bands spanning the planet's northern and southern hemispheres just beneath the Martian surface. But until now, researchers had not been able to confirm the glacial chemical makeup.

But new radar observations, detailed in the latest issue of Nature, offer some clarity. By studying the movement of the frozen formations over time and comparing the glaciers' behavior with hydraulic models, scientists were able to confirm the presence of H2O.

"We have looked at radar measurements spanning ten years back in time to see how thick the ice is and how it behaves," lead study author Nanna Bjornholt Karlsson, a climatologist and glacial expert at the University of Copenhagen's Niels Bohr Institute, said in a press release.

"A glacier is after all a big chunk of ice and it flows and gets a form that tells us something about how soft it is," Karlsson added. "We then compared this with how glaciers on Earth behave and from that we have been able to make models for the ice flow."

Karlsson and her colleagues also re-examined radar observations to calculate the total mass of the thousands of glacial formations observed within the frozen belts. By studying the flow of the formations, scientists were able to make a more accurate estimation of the glaciers' volumes.

"We have calculated that the ice in the glaciers is equivalent to over 150 billion cubic meters of ice -- that much ice could cover the entire surface of Mars with 1.1 meters of ice," Karlsson explained. "The ice at the mid-latitudes is therefore an important part of Mars' water reservoir."

Scientists say the layer of Martian dust covering the glacial belts has protected the frozen ice, preventing its evaporation in the planet's thin atmosphere.