Next Mars lander may miss water opportunity

Beagle 2 is the next lander scheduled to fly to Mars

The scientist behind the next scheduled mission to put a lander on Mars says his craft may not be able to visit the sites where Nasa researchers think there is evidence of recent running water.

If you don't have water as a solvent, you cannot have life

Prof Colin Pillinger

Professor Colin Pillinger, of the Open University, UK, is leading the team building Beagle 2.

The surface probe is part of the European Space Agency's (Esa) Mars Express mission set to fly in 2003.

Beagle 2's landing site still has to be finalised, but Professor Pillinger says the craft's design means it can only come down in a limited number of areas on Mars.

Location critical

If the location were at too high a latitude, as is suggested by the Nasa announcement, it would require the probe to have bigger parachutes to brake its descent. This would have to be ruled out because of payload constraints, says Professor Pillinger.

Mars Global Surveyor image showing channels that were probably cut by recent seepage of water

A high latitude would also necessitate bigger batteries to keep the lander warm in the colder temperatures near the Martian poles.

"What we have to hope is that they will put their finger on places that are close to the Equator and preferably below the Martian datum, which is the Martian equivalent of below sea level," the OU scientist says.

"The bottom of Vallis Marineris would be very nice," referring to a deep system of spectacular canyons, 4,000 kilometres (2,500 miles) long and up to seven kilometres (4.5 miles) deep.

Nasa missions

After losing two Mars spaceprobes last year, Nasa altered its plans to explore the planet. It cancelled all missions except an orbiting survey satellite.

Professor Pillinger: Landing sites are limited

Nasa is now expected to perform an urgent re-evaluation about landing a probe in the regions thought to have had recent running water.

Nasa has said that to look for life on Mars you have to look for the water. Some believe that life could have developed there billions of years ago when the planet was wetter and warmer and could be now hanging on in such an oasis.

"The primary ingredient of life is water. If you don't have water as a solvent, you cannot have life," Colin Pillinger said.