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Frozen sea suggests possible life on Mars today, researchers say

This is the first evidence of there having been recent liquid water on Mars, added researchers from the international team of scientists who reported the discovery.

Higher levels of methane over the same area mean that primitive microbes might survive on Mars today, the researchers said. Methane is produced by many types of microbes. 

The images of pack ice near the Martian equator were taken by the a stereo camera on the European Space Agency’s Mars Express probe.

The results of the work by the team lead by John Murray of Open University, Jan-Peter Muller of University College London, and Gerhard Neukum of the Free University of Berlin were presented at an European Space Agency Mars Science Conference at ESTEC, Netherlands on February 21, and are to be published in the scientific journal Nature next month.

Muller said: “This is a historic moment for Mars exploration when a previously neglected region reveals its secrets. Speculations that this area might have water close to the surface have been shown to be correct.” 

Murray, of the Department of Earth Sciences at the OU, said: “The fact that there have been warm and wet places beneath the surface of Mars since before life began on Earth, and that some are probably still there, means that there is a possibility that primitive micro-organisms survive on Mars today. This mission has changed many of my long-held opinions about Mars – we now have to go there and check it out.”

The water that formed the sea appears to have originated beneath the Martian surface, the researchers said. Erupting about 5 million years ago, from a series of fractures known as the Cerberus Fossae, the water flowed down in a catastrophic flood, collecting in an area 800 x 900 km (about 500 x 562 miles) and was initially an average of 45 metres deep. This means it was about the same size and depth as the North Sea. The pack ice, which formed on the surface of the sea, drew the attention of Mars Express scientists.

Although formed at the time when early hominids on Earth were evolving from apes, this is very recent in geological terms, the researchers said. This suggests that vast flooding events, which are known to have occurred from beneath Mars’ surface throughout its geological history, still happen, they explained. 

The presence of liquid water for thousands of millions of years, even beneath the surface, is a possible habitat in which primitive life may have developed, and might still be surviving now. the researchers claimed. This is now a prime site for future missions looking for life, they added.

The pack-ice floes have drifted into obstacles, and in places have become grounded on islands when the water level dropped, but the very flat surface (similar in slope to water surfaces in estuaries on Earth when the tide is coming in) and the thick ice within enclosed craters suggests that most of the ice is still there. 

Ice is unstable at the surface of Mars because of the low atmospheric pressure, and sublimes away (vaporizes directly without first becoming water) into the atmosphere. But the frozen sea appears to have been protected from this by a layer of volcanic ash and dust, the scientists said.

The Mars Express probe will deploy a ground-penetrating radar in May designed to look for ice or water beneath the surface. If water ice is confirmed, this site represents a prime target for space life-seeking missions planned by the European Space Agency for the end of this decade, the researchers said. 

Mars Express, Europe’s first mission to another planet, entered the orbit of Mars on Christmas Day 2003, and since January 2004 the high resolution stereo camera on board has been taking many stereo images of the surface from altitudes as low as 270 km (169 miles). This shows details down to 10 metres (about 10 yards). 

Around 23% of the Martian surface has now been covered by the camera in 3D and colour.

The 3D information means that, for the first time, scientists are able to make detailed measurements of such quantities as dip and thickness of surface layers on another planet, just as geologists do on the Earth. 

The images also provide information on past climate and water, as well as the relative ages of the surface from crater measurements on Mars, volcanism, potential resources, characteristics of present and future landing sites, and observations of Mars’ two tiny moons, Phobos and Deimos.

—EJL

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