Mars' dusty surface hides 150 trillion tons of glacial water ice

Thursday, April 9, 2015, 11:36 AM - Mars may not be as dry as it appears, as new research has revealed that there's enough water locked away in buried glaciers to coat the entire planet in a metre-thick crust of ice.

We've been hearing plenty of reports over the past few years about how Mars was once a much warmer, wetter planet. Additionally, based on satellite imagery, researchers have determined that a good deal of Mars' original water might still be there, frozen solid into glaciers and locked away in the planet's mid-latitudes, under layers of dust and dirt.

However, until now, there was no indication of exactly how much of this water ice was actually there.

Now, based on roughly a decade of radar data collected by NASA's Mars Reconnaissance Orbiter, along with knowledge of how glaciers flow here on Earth, scientists at the Niels Bohr Institute's Centre for Ice and Climate have used computer models to give us a good idea.

"We have calculated that the ice in the glaciers is equivalent to over 150 trillion cubic metres of ice - that much ice could cover the entire surface of Mars with 1.1 metres of ice," Nanna Bjørnholt Karlsson, a post-doc researcher at the Centre for Ice and Climate, said in a statement.

According to Karlsson, these glaciers make up an important part of Mars' water reservoir.

“We have looked at radar measurements spanning ten years back in time to see how thick the ice is and how it behaves," explains Karlsson. "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. We then compared this with how glaciers on Earth behave and from that we have been able to make models for the ice flow."

Although Mars does have ice at its poles, higher temperatures and lower air pressure in the planet's mid-latitudes and equatorial region would mean any exposed ice would quickly evaporate off into space. Thus, if these thick glaciers are still around, they must be buried under thick layers of dust to be protected from that process.

Correction: A previous version of this article quoted Dr. Karlsson as saying "billion cubic metres of ice." Whereas that quote is directly from the source, it reflects the long-scale numbers used in the European Union. This has since been corrected above to "trillion cubic metres," to reflect the short-scale numbers used in North America. We apologize for any confusion this may have caused.

Sources: Niels Bohr Institute | NASA/ESA/Hubble | ESA/Hubble (M. Kornmesser & L. L. Christensen)