Life on Mars was possible more than a billion years later than originally thought, according to new findings from NASA.
The Mars Reconnaissance Orbiter’s Context Camera and High Resolution Imaging Science Experiment camera have captured images of what were once massive rivers and lakes fed by snow meltwater from surrounding valleys.
These features formed far more recently than the previously-known era of wet conditions in the distant history of the Red Planet, some 1 billion years later, according to the space agency.
Sharon Wilson of the Smithsonian Institution, Washington, and the University of Virginia, Charlottesville said in statement. “We discovered valleys that carried water into lake basins. Several lake basins filled and overflowed, indicating there was a considerable amount of water on the landscape during this time.”
Data from NASA’s Mars Global Surveyor and the European Space Agency’s Mars Express was also used to evaluate the streams, lakes and valleys which were discovered in the planet’s northern Arabia Terra region, which extend for some 90 miles (150km).
“One of the lakes in this region was comparable in volume to Lake Tahoe,” said Wilson, referring to the lake in the western United States that holds about 45 cubic miles (188 cubic km) of water.
“This particular Martian lake was fed by an inlet valley on its southern edge and overflowed along its northern margin, carrying water downstream into a very large, water-filled basin we nicknamed ‘Heart Lake.'”
This lake held an impressive 670 cubic miles of water (2,790 cubic km), more than in Lake Ontario of the Great Lakes.
To age the fresh shallow valleys in the Arabia Terra region, Wilson and her researchers estimated how long ago 22 impact craters in the area were formed and, looking at surrounding debris from the craters, judged whether the valleys or craters came first.
They concluded that this wet era on the Red Planet occurred 2-3 billion years ago, well after it was believed most of Mars’ original atmosphere had been lost and water on the planet had frozen.
This, according to NASA, “suggests the surface conditions at this later time may also have been suitable for microbial life.”
“The rate at which water flowed through these valleys is consistent with runoff from melting snow,” Wilson said. “These weren’t rushing rivers. They have simple drainage patterns and did not form deep or complex systems like the ancient valley networks from early Mars.”
Source: Word News