Tuesday, January 12, 2010

Ancient lakes found on Mars 'may have hosted life'


Ancient lakes found on Mars 'may have hosted life'
New evidence of ancient lakes and rivers on Mars has been found by British scientists, increasing the likelihood that there was once life on the Red Planet.
By Kate Devlin and Louise Gray
05 Jan 2010

Link to this video An analysis of satellite images revealed craters left along Mars' equator by lakes similar to those found in Alaska and Siberia.

Importantly, the lakes were linked by small tributaries and rivers, suggesting water was moving which means they would have been able to support microbial life, scientists including a team from Imperial College London found.

Droplets on Mars Phoenix Lander indicate waterThe lakes, up to 12 miles long, have been dated back three billion years and were probably created following volcanic activity in the region around the equator, which was previously thought to be dry and arid.

Previously scientists believed that the lakes on Mars during that period were merely ice so the findings widen the period of time in which now extinct life forms could have existed on Mars, researchers believe.

The results come just months after Nasa, the American space agency, announced that they had found water on the surface of the planet, raising more hopes that signs of life could some day be discovered.

Previous research has shown that Mars was home to lakes and rivers earlier in its history, around four billion years ago.

But scientists now believe that during the Hesperian Epoch, around three billion years ago, they could also have been created by sporadic wet and warm periods, according to the research published in the journal Geology.

Researcher Dr Sanjeev Gupta, from Imperial College, said: "Potentially life could have survived in these lakes, we would be talking about microbial life.

"But these are a potential place to go and look for that life. Previously it was thought that it would have been difficult to sustain life during the period, because it was too cold and dry and there was no standing water, such as ponds, which is what you need for life.

“But now we have shown that there was standing water, this is another avenue to explore.”

Future robotic missions to the planet to search for signs of life should include explorations in the areas around the lakes, he added.

Although they have long been dry, deep impressions of the bodies of water remain on the surface of the planet.

The latest findings, published in the journal Geology, used satellite images taken by Nasa’s Mars Reconnaissance Orbiter.

These were then analysed to estimate the age of the craters and to discover the channels leading from them.

The lakes were probably created following volcanic activity, meteorite impacts or shifts in the orbit of the planet, all of which could have created warmer conditions in which ice melted to creates the lakes and rivers.

The researchers now plan to focus on other areas along the planet’s equator to discover how widespread an area these lakes covered.

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