Glaciers on Mars contain enough water to cover the entire planet to a depth of more than 3 feet, according to a new study out of Denmark.
These Martian glaciers are present not just near the poles but also extend toward the equator, the new study concluded. On Mars, ice coverage at the North Pole is significantly larger than at the South Pole. Dust on the surface of the Red Planet could be covering vast glaciers, leading researchers to theorize that Mars could hold much more water than previously believed. Investigators calculate that if all of this ice were to melt, the world would be covered in the liquid to a depth of more than three-and-a-half feet.
The Mariner 9 mission, which arrived at Mars in 1971, provided the first evidence of ancient water on the Martian surface. For several years, scientists have known that glaciers exist just beneath the surface of the Red Planet but were uncertain whether the formations were composed of frozen carbon dioxide, water or mud. Data from the Mars Reconnaissance Orbiter (MRO), launched in 2005, revealed the glaciers were primarily composed from water. In an effort to determine the quantity of water trapped in the glaciers, researchers compared observational data and computer modeling of ice flows.
"We have looked at radar measurements spanning 10 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," Nanna Bjørnholt Karlsson of the Niels Bohr Institute at the University of Copenhagen said.
Thousands of glaciers were found in both the northern and southern hemispheres. Data on the presence of known glaciers was more detailed than in other regions. Investigators took information learned from better-studied regions and applied models to "fill in" areas not seen in other areas.
"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. The ice at the midlatitudes is therefore an important part of Mars' water reservoir," said Bjørnholt Karlsson.
Atmospheric pressure on Mars is so low that any exposed ice instantly disappears, turning into water vapor. Dust on top of the features could protect the glaciers, preserving the stores of ice.
Analysis of the size and extent of glaciers on Mars was profiled in the journal Geophysical Research Letters.
