A new study states that the glacial belts that hide under Mars’ surface dust contain enough water to cover the entire planet.
With the help of the many satellites that orbit Mars, astronomers have been able to observe the shape of glaciers just below the surface. For a long time they did not know if the ice was made of frozen water (H2O) or of carbon dioxide (CO2) or whether it was mud. Using radar measurements from the Mars Reconnaissance Orbiter, astronomers have been able to determine that it is water ice.
The astronomers stated that Mars has belts of glaciers at its central latitudes in both the southern and northern hemispheres, apart from distinct polar ice caps. They appear as surface ground because a thick layer of dust covers the glaciers. But radar measurements show that they are glaciers that are composed of frozen water. A study, which was published in the Geophysical Research Letters journal, has now calculated the size of the glaciers and thus the amount of water in the glaciers, which is equivalent of all of Mars being covered by more than one meter of ice.
Nanna Bjørnholt Karlsson, a postdoctoral student at the Niels Bohr Institute at the University of Copenhagen, and the lead author of the study, said, “We have looked at radar measurements spanning ten years back in time to see how thick the ice is and how it behaves. 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.”
The astronomers have obtained solid high-resolution data for some regions of Mars, but only sparse data was available for other areas. To s9lve this problem they filled the lacking data with information about ice flow taken from better-studied areas of Mars. This method allowed them to calculate how thick and voluminous the ice is across the glacial belts. The fact that the ice has not evaporated told them that the layer of dust acts as protection.
“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,” added Karlsson.