Life on Mars? A little Beagle may tell us

This image shows a simulation of the three airbags separating to release the Beagle 2 lander onto the surface of Mars. Europe's mission to search for life on Mars cleared a vital hurdle on December 19 as its unmanned orbiter ejected a probe that should land on the Red Planet on Christmas Day. PHOTO: AFP

The 400-million-kilometer (250-million-mile) voyage of Beagle 2 culminates Europe's first solo mission to explore other planets, and places the continent in pole position in a race with the United States to answer one of the greatest puzzles in space.

"For 5,000 years, people have looked at Mars and wondered if there is life there, and it falls to this generation to do it," said Beagle 2's lead scientist, Colin Pillinger, a professor at Britain's Open University.

"The question that is uppermost in my mind is, 'Are we alone in the Universe?'

"Finding that we are not alone in respect of our Solar System would mean to me that the Universe is teeming with life."

On December 25, six days after it was released like a gently spinning top from its mother ship, Mars Express, Beagle will plunge into the thin martian atmosphere at more than 20,000 kilometers (12,500 miles) per hour, with a conical shield soaking up the initial heat from friction.

Then a parachute should open to slow the descent until, in the final stages, gas bags will inflate around the lander, bringing it to a bouncing halt at 0254 GMT in Isidis Planitia, a flat sedimentary basin near the equator.

If all goes well -- a mighty if, given that the payload (less than 69 kilos, 152 pounds at launch) is highly sophisticated and there are fears that vicious dust storms are brewing on Mars -- Beagle will then open out like a fob watch, and four solar panels will flop out.

At 0630 GMT, the little lander has its first chance to send the folks back home a sign of life, which should include a radio callsign composed by the British pop band Blur.

Then, after a check to ensure that its systems are OK, Beagle 2 can start to move a robot arm, a triumph of miniaturisation that has seven tiny tools designed mainly to assess whether water exists or has existed on Mars and whether there are the remains of carbon-based lifeforms on its ruddy surface.

In orbit overhead will loop the unmanned Mars Express, stuffed with sensors to closely map the martian surface, analyse its atmosphere and peer beneath the surface dust and rocks with ground-penetrating radar.

The reason for the big uncertainty is that there is a lot of evidence that if Mars is cold and dry today, it was once in its early history, perhaps 3.8 billion years ago, warm and wet.

If liquid water did flow, could life have evolved there? And where is the water now? Images sent back to Earth from US orbiters suggest that there could be abundant underground water, or that there was until recently.

Mars has always cast a spell on Earth, either as a divine body, a fictionalised source of invasion (H.G. Wells' "The War of the Worlds") or as Earth's verdant twin (Ray Bradbury's "The Martian Chronicles").

Dreamers see it as mankind's first colony in space, a stepping stone to a wider conquest of the Solar System and, who knows, the galaxy beyond.

But the history of exploration of this planet is a graveyard of broken dreams.

Of the 32 probes sent to Mars since 1960, only nine have been a success.

Nineteen were outright failures, the latest of which was Japan's probe Nozomi, which was abandoned on December 9 after its electronics were damaged by a solar flare.

Beagle 2 is named in honour of HMS Beagle, the ship that took Charles Darwin, the pioneer of the theory of evolution, on his historic 1831-36 trip around the world.