The discovery increases the chances of life existing on the planet in the recent past, or even surviving today.
Scientists have identified fan-like gullies inside a crater that appear to be younger than 1.25 million years old.
They believe the channels must have been sculpted by surface water from melting ice.
There is evidence of waterborne sediments being carried down from high ground and deposited in low-lying alluvial fans.
Professor James Head, from Brown University in Providence, Rhode Island, who with colleagues reported on the discovery in the journal Geology, said: "We think there was recent water on Mars. This is a big step in the direction to proving that."
The gully system is in Promethal Terra, an area of cratered highlands south of the Martian equator.
A powerful camera on the American space agency Nasa's Mars Reconnaissance Orbiter spacecraft was able to distinguish four individual lobes of deposited material in the fan system.
One was pockmarked with small craters linked to a rayed crater 80 kilometres away known to be 1.25m years old.
This lobe was likely to be about the same age. The other three lobes were unblemished and therefore had to be younger, said the scientists.
They believe the best explanation for the gullies is melting snow and ice rather than groundwater bubbling up to the surface.
The finding follows discoveries of water-bearing minerals such as opals and carbonates on Mars.
Experts now think the planet was occasionally wet for far longer than was previously believed.
by:telegraph
Wednesday, March 04, 2009
Subscribe to:
Post Comments (Atom)