NASA scientists are reportedly turning to Mexico for help in their search for extraterrestrial life. The space agency believes that a network of 170 lakes around the town of Cuatro Cienegas could hold clues to the conditions prevalent on Earth when life began.

The lakes, which have a species diversity that rivals the Galapagos Islands, were formed by a departing sea, around 100 million years ago. They also contain clumps of calcified bacteria, called stromatolites. Within these rocky structures, conditions are similar to those on Young Earth.

NASA researchers think that by studying conditions at the lakes, they will be able to work out what kind of atmospheric conditions would be created by primitive life, Reuters reports, so that they will recognise it when they see it on other planets.

The hunt for rocky planets will begin in earnest when NASA launches its planned "Terrestrial Planet Finder" telescope in 2014. This will be able to take pictures of rocky worlds orbiting stars as many as 45 light-years away. Currently, although scientists have identified nearly 150 extrasolar planets, all of them are gas giants, bigger than Jupiter.

Researchers have collected gas readings, chemical samples and cell samples from the bacteria. The results will be used to fine-tune computer models of life-friendly atmospheres on various simulated planets. ®

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