Articles | Was there life on Mars?

Was there life on Mars?

Published: Thursday, 17 July 2008, 8:06AM

Mars was once covered once by lakes, rivers and other bodies of water that could have supported life, according to scientists.

Stunning mages from US and European spacecraft have revealed details of regions thought to contain water-bearing minerals and geological formations formed billions of years ago.

The High-Resolution Stereo Camera onboard the European Space Agency's Mars Express took pictures of Echus Chasma, thought to have been one of the largest sources of water on Mars.

Echus Chasma resembles a dry riverbed 60 miles long and six miles wide and cuts through the Lunae Planum high plateau north of Valles Marineris, the so-called Grand Canyon of Mars.

Last month, the Mars Phoenix Lander found ice and alkaline soil on the surface of the Red Planet, indicating it was left over from warmer, wetter times.

A team from Brown University used the Compact Reconnaissance Imaging Spectrometer for Mars (Crism) and other instruments on board Nasa's Mars Reconnaissance Orbiter to look at colours in reflected sunlight which helped determine what minerals were there.

The clay-like minerals, called phyllosilicates, suggest water interacted with rocks dating back to what is called the Noachian period on Mars, about 4.6 billion to 3.8 billion years ago.

One of the Brown researchers, John Mustard, said: "This is really exciting because we're finding dozens of sites where future missions can land to understand if Mars was ever habitable and if so, to look for signs of past life."

He continued: "The minerals present in Mars' ancient crust show a variety of wet environments. Water must have been creating minerals at depth to get the signatures we see.

"What does this mean for habitability? It's very strong. It wasn't this hot, boiling cauldron. It was a benign, water-rich environment for a long period of time."

"In most locations the rocks are lightly altered by liquid water, but in a few locations they have been so altered that a great deal of water must have flushed though the rocks and soil."

Scott Murchie, Crism's principal investigator at the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, said: "The big surprise from these new results is how pervasive and long-lasting Mars' water was, and how diverse the wet environments were.

Another study found the wet conditions persisted for a long time and there was evidence of river channels forming a delta where the river emptied into a crater lake.

Brown University's Bethany Ehlmann said: "The distribution of clays inside the ancient lakebed shows that standing water must have persisted for thousands of years.

"Clays are wonderful at trapping and preserving organic matter, so if life ever existed in this region, there's a chance of its chemistry being preserved in the delta."