Nasa images reveal 'new Mars' [+pictures]

This view of Mars taken by Nasa's Mars Reconnaissance Orbiter spacecraft on October 1, 2006 and released October 16, shows diverse materials and morphologies in the region south of Mawrth Vallis on Mars. Picture / Reuters

PASADENA, California - A Nasa spacecraft orbiting Mars is using the most powerful cameras ever pointed at the Red Planet to study its climate cycles and whether there is enough water to support a manned mission, scientists at Nasa's Jet Propulsion Laboratory said today.

Images taken during a test of the Mars Reconnaissance Orbiter's instruments showed clay-rich areas that could have supported life and frost, and layered deposits of ice and dirt at the polar ice cap indicate "dynamic climate changes" as recently as 100,000 years ago, scientist Scott Murchie said.

"We are seeing a new Mars," project scientist Richard Zurek said at a news conference. "We are seeing information comparable to, or better than, what you could see flying over Earth in a commercial airliner."

Launched in August 2005, the orbiter dropped into a low orbit around Mars last month to map the planet's subsurface minerals, monitor its atmosphere and look for evidence of enough subsurface ice or water to process into oxygen, concrete and rocket fuel for manned exploration.

President George W. Bush has urged Nasa to focus on getting people to the moon and Mars, although a manned mission to Mars is still many years away.

The Mars orbiter has the most advanced and powerful instruments of four science satellites circling the planet and will return more than 10 times the quantity of data during its two-year mission than all the other probes combined.

The orbiter will also use HiRISE, its super high-resolution camera, to find landing sites for the Phoenix Mars Lander, set to arrive in 2008, and for the 2009 arrival of the Mars Science Laboratory, a larger version of the twin robotic geologists Spirit and Opportunity, which have been traversing the planet's surface since 2004.

Carved by water

The super high-resolution photographs, snapped from 290km above the planet's surface and showing chair-sized details, show how water carved the arid planet's landscape into fan-shaped soil deposits, deep cut chasms and gullies and layers of ice and dust.

In the Mawrth Vallis region near Mars' midsection, spectrometry of the eroded surface revealed clay deposits that formed in a variety of wet conditions such as standing water and streams, Murchie said.

The conditions could have given rise to microorganic life on ancient Mars, Murchie said.

The orbiter's cameras also recorded melting frost in the folds of gullies and hummocks near the edge of the Terra Sirenum crater in Mars' southern hemisphere.

"This is something that formed over a number of events. Water flowed in this area and was geologically recent. The water dates from the current geological age," mission scientist Alfred McEwan said.

Images of Chasma Boreale, a valley that cuts deeply into the northern polar cap, showed layers of ice and dirt whose composition varied widely, a sign of radical climate change.

The composition of oldest layer of polar cap ice was similar to the newest, meaning that the concentration of dust in the Martian atmosphere could be influenced by planetary movement.

The scientists have already gathering data that they hope will tell them how much water vapour escaped the planet's relatively thin upper atmosphere.

- REUTERS