The scientist behind Europe's lander mission to Mars has launched an extraordinary attack on the American space agency, Nasa, and its plans to return to the Red Planet.

I'm swapping sightseeing by Athena for science on Beagle 2

Prof Colin Pillinger

Professor Colin Pillinger said the agency's twin rovers would be engaged in little more than a jaunt around the planet's rocky surface when they touch down in 2004 and would be part of some questionable science.

He claimed Europe's static lander, named Beagle 2, would achieve far more than Nasa's so-called Athena package and at a fraction of the cost.

"I'm swapping sightseeing by Athena for science on Beagle 2," Professor Pillinger told the British Association's Festival of Science.

The race is well and truly on with both Nasa and the European Space Agency, Esa, using a favourable Mars-Earth alignment in 2003 to launch missions to the Red Planet.

Life's 'lubricant'

Nasa is sending two "mobile laboratories", at a combined cost of about $500m (�350m), which are scheduled to land on Mars within a couple of weeks of each other in January of 2004. The 140-kg rovers will move up to 100 metres a day across the planet's surface.

The Nasa rovers will cover up to 100 metres a day

Esa's Mars Express mission will arrive at Mars just before the Athena rovers, dropping the static Beagle 2 lander on to the surface near the planet's equator.

Beagle 2, which has a real cost in excess of �30m ($40m), has a mechanical mole that will burrow out into the surrounding area to retrieve samples for analysis.

Both Nasa and Esa have the stated aim of looking for signs of life - past or present - and in particular water which Professor Pillinger has called the "lubricant" for life.

But the Open University-based researcher questioned the quality of some of the rovers' equipment.

"Nasa's Athena has an inferior complement of science instruments," he said. "Indeed, their spectrometers are geared up for looking for hydrogen rather than water - they will infer water is present if they find hydrogen."

Methane key

In contrast, he claimed Beagle could confirm the presence of organic matter, water and minerals that have been deposited from water such as carbonates.

Beagle 2 is going on Esa's Mars Express mission

"It can measure their quantitative abundance and their isotopic compositions," the professor said. "This suite of information is absolutely key for deciding whether life ever took place on the planet in the past."

And he told reporters that the presence of methane would be the big test of whether life still existed on Mars.

"Methane is a species which should not be there unless biology is continuously supplying it. The chemical state of the Martian atmosphere is such that hydrocarbons would get oxidised away in about 300 years."