Article Posted on : - Jul 31, 2010

LONDON (PTI): Scientists have identified rocks which they claim could contain evidence of life on Mars.

An international team, led by the Search for Extraterrestrial Intelligence Institute (SETI) in California, has made the discovery in the ancient rocks of Nili Fossae, the 'Earth and Planetary Science Letters' reported.

Their work has revealed that the ancient rocks of Nili Fossaeare are almost identical to those in the Pilbara region of north-west Australia where some of the earliest evidence of life on Earth was recorded and preserved in mineral form.

In fact, the scientists claim the same "hydrothermal" processes that preserved these markers of life on Earth could have taken place on the Red Planet at Nili Fossae.

The study found that the ancient rocks shared similar minerals and features, known as "stromatolites". It is significant because Pilbara is used to study the early stages of life on Earth 3.5 billion years ago.

Adrian Brown from the Seti Institute, who led the research, told 'BBC News': "Life made these features. We can tell that by the fact that only life could make those shapes; no geological process could.

"If there was enough life to make layers, to make corals or some sort of microbial homes, and if it was buried on Mars, the same physics that took place on Earth could have happened there."

The Nili rocks, which have existed for three-quarters of the history of Mars, are four billion years old and contain carbonates, first discovered in 2008.

Carbonate, which exists in the fossilised remains of shells and bones, is formed when water and carbon dioxide mix with calcium, iron or magnesium. Its discovery countered the theory that all water on Mars was at one time acidic and was the clearest evidence yet that it was habitable.