In addition to polar ice caps, Mars has glaciers and according to new research there is enough water in those glaciers to cover all of Mars in more than one meter of ice.
A thick layer of dust covers the glaciers which makes them look like the rest of the surface of the Red Planet. That dust also makes them difficult to study. For many years researchers did not know whether the glaciers were made of mud, frozen carbon dioxide or frozen water.
Using radar measurements from the Mars Reconnaissance Orbiter, researchers have determined that the glaciers are made of water, just like the glaciers on Earth. Using further radar observations and ice flow modeling, a group of researchers from the Niels Bohr Institute have calculated the thickness of the ice.
“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,” said Nanna Bjørnholt Karlsson in a statement.
Karlsson is a postdoc at the Centre for Ice and Climate at the Niels Bohr Institute at the University of Copenhagen and an author of a study published in the journal Geophysical Research Letters</a>.
According to Karlsson the glaciers are located between the latitudes of 300 and 500 and are present in both the northern and southern hemispheres. Data on some areas of glacial coverage are better than others so the poorly analyzed areas were estimated. To do this researchers used high-resolution data on the flow and form of glaciers for which strong data exists. Using this data the researchers calculated the thickness and volume of the Martian glacial belts.
“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 mid-latitudes is therefore an important part of Mars’ water reservoir,” explains Karlsson.
For those who see Mars as a potential future home for humans, this is both good and bad news. It means that there is a great deal of water available on Mars. Unfortunately, according to the researchers, the thick dusty coverings are the only reason that the water is still present at all.
Mars has such a thin atmosphere that the pressure is inadequate to maintain liquid water for very long. Water ice rapidly evaporates and becomes water vapour. That means that exposing the glaciers would cause them to vanish fairly quickly.
It appears that, were it not for the atmosphere, Mars could have easily been a water world similar to Earth. Another recent study suggests that Mars once had, and lost, an amount of water equivalent to the volume of the Arctic Ocean.
When added to the glaciers, with enough water to cover the entire planet a meter deep, and the polar caps it paints a picture of a very wet world. There is also a strong possibility of underground water and ice on Mars. However, without the ability to prevent the water from evaporating and escaping into space, rivers, lakes and oceans are currently impossible.
