Could life on Mars have existed just 200,000 years ago? Young rock formations provide evidence of 'recent' water on the red planet
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Water flowed on the surface of Mars as recently as 200,000 years ago, new research suggests.
A young crater in the red planet's southern hemisphere contains well-preserved gullies and sediment deposits thought to have been formed by water.
Scientists studying the crater estimated it to be no more than about 200,000 years old, so the water features must have appeared since then, the scientists claim.
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This photo shows debris flowing on Mars (top and bottom left). The Martian landforms were shown to be similar to known debris flows on the Norwegian Svalbard islands in the Arctic Ocean (bottom right)
The crater formed long after the most recent proposed ice age on Mars, which ended some 400,000 years ago.
'Gullies are common on Mars but the ones which have been studied previously are older, and the sediments where they have formed are associated with the most recent ice age,' said lead scientist Dr Andreas Johnsson, from the University of Gothenburg in Sweden.
'Our study crater on Mars is far too young to have been influenced by the conditions that were prevalent then.
The crater formed long after the most recent proposed ice age on Mars, which ended some 400,000 years ago. This is an artist's impression of what a lake on Mars may have looked like
EVIDENCE OF WATER ON MARS
Evidence of water on Mars dates back to the Mariner 9 mission, which arrived in 1971. It revealed clues of water erosion in river beds and canyons as well as weather fronts and fogs.
Viking orbiters that followed caused a revolution in our ideas about water on Mars by showing how floods broke through dams and carved deep valleys.
Mars is currently in the middle of an ice age, so liquid water cannot exist on its surface at the present time. However, the planet seems to have been warmer and wetter in the past.
In June last year, Curiosity found Powerful evidence that water good enough to drink once flowed on Mars. In September, the first scoop of soil analysed by Curiosity revealed that fine materials on the surface of the planet contain two per cent water by weight.
'This suggests that the melt water-related processes that formed these deposits have been exceptionally effective also in more recent times.'
The crater had features that were characteristic of debris flows on Earth caused by material being carried and then deposited by fast-moving water.
The Martian landforms were compared with known debris flows on the Norwegian Svalbard islands in the Arctic Ocean.
'Our fieldwork on Svalbard confirmed our interpretation of the Martian deposits,' said Dr Johnsson, whose findings appear in the scientific journal Icarus.
'What surprised us was that the crater in which these debris flows have formed is so young.'
The study crater is located in the mid-latitudes of the Martian southern hemisphere and superimposed on the 'rampart ejecta' of a nearby larger crater.
Rampart ejecta, which display flower-like features, are believed to be the result of a meteor impact on wet or icy ground.
The scientists first thought the recent water flow features had come from preserved ice within the rampart ejecta.
However, structures such as faults or fractures that could have acted as conduits for the melt water were missing.
'It is more likely that the water has come from melting snow packs, when the conditions were favourable for snow formation,' said Dr Johnsson.
'This is possible since the orbital axis of Mars was more tilted in the past than it is today.'
Evidence of water on Mars dates back to the Mariner 9 mission, which arrived in 1971. It revealed clues of water erosion in river beds and canyons as well as weather fronts and fogs.
Viking orbiters that followed caused a revolution in our ideas about water on Mars by showing how floods broke through dams and carved deep valleys.
Mars is currently in the middle of an ice age, so liquid water cannot exist on its surface at the present time. However, the planet seems to have been warmer and wetter in the past.
In June last year, Curiosity found Powerful evidence that water good enough to drink once flowed on Mars. In September, the first scoop of soil analysed by Curiosity revealed that fine materials on the surface of the planet contain two per cent water by weight.
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