Grand Canyon of Mars: From 150 miles up, the amazing pictures that bring the Red Plan

Grand Canyon of Mars: From 150 miles up, the amazing pictures that bring the Red Planet to life

By JULIE WHELDON - More by this author » Last updated at 00:08am on 16th February 2007 Comments

It is the holy grail of space exploration to prove there has been life on Mars. These extraordinary pictures take mankind one step closer to that great discovery.

Some of the most detailed images ever captured of the planet's surface provide clear evidence that water once flowed there in abundance, further strengthening evidence that it once supported life.

VIDEO: Watch computer-generated footage of Nasa's latest space missions

This stunning image reveals signs of abundant ground water that may have flowed through the rock millions of years ago

The conclusion comes from examination of the giant valley which slices across the picture. The gash is the Chandor Chasma canyon, part of the great martian Rift Valley which in places is seven times deeper than the Grand Canyon and is the deepest fissure on any planet in the solar system.

Transplanted on Earth, the valley just south of the martian equator, would stretch across the United States.

The new photographs show the canyon walls are clearly composed of alternating light and dark-toned layers, shot through with fractures which are surrounded by 'halos' of light-toned bedrock amid the dark bands.

Scientists believe these are zones where the rock has been altered, either through cementing or bleaching, by water emerging from some vast underground reservoir millions or even billions of years ago.

Chris Obuku, who analysed the images at the University of Arizona, said: "On Earth bleaching of rock surrounding a fracture is a clear indication of chemical interactions between fluids circulating within the fracture and host rock."

Based on the images, he concluded that fluids - probably water, liquid carbon dioxide, or a combination of the two - once flowed abundantly just below the surface in this area.

The pictures, revealed at the American Association for the Advancement of Science conference in San Francisco and published in the journal Science, were taken from Nasa's Mars Reconnaissance Orbiter which has been circling the planet for a year.

The spacecraft's camera is so powerful it can pick out features measuring just 12in across from its vantage point 150 miles above the surface. The orbiter has also captured stunning images of other regions. They include Becquerel Crater in Arabia Terra, a densely cratered zone in the northern hemisphere, where rock layers can also be seen.

Mars formed more than 4.5billion years ago and the first images of its surface from the Sixties suggested little more than a dusty cratered world rather like the Moon. But thanks to technological advances we now know it is home to deep canyons, ice cliffs half a mile high and volcanos the size of Texas.

Scientists believe Mars at one time had a climate similar to that found on earth today and could have been home to lakes, streams and flowing water.