Supporters of the "life on Mars" theory have been dealt a blow by NASA which says the intense ultraviolet radiation penetrating the thin atmosphere of the Red Planet produces an abundance of oxygen ions that destroy organic molecules, the building blocks of life.
By simulating the Martian surface environment in a laboratory, scientists have found that a combination of ultraviolet radiation, mineral grain surfaces, atmospheric oxygen and extremely dry conditions produces superoxide ions. But signs of life under the surface and inside rocks have not been ruled out.
Meanwhile, the UK's 30kg (66lb) Beagle 2 Mars lander, which is flying to the Red Planet piggyback on the European Space Agency's Mars Express orbiter, is likely to land in the Isidis Basin region just north of the Martian equator in 2003. A final decision will be made in December. The Isidis Basin, relatively free of rocks and boulders which could spoil the landing, resembles a desert but at the same time shows evidence of ancient floods.
Colin Pillinger, the UK's Open University professor who is developing the Beagle 2, claims that NASA's two Rover missions also planned for launch in 2003 will be "much less scientifically accomplished".
The $50 million Beagle 2 compares with NASA's $600 million 150kg twin Rover mission but will penetrate the Martian soil for signs of water and life, while the Rovers will be studying the Martian ecology and looking for indirect evidence of water.
"Unlike the Rovers, Beagle 2 won't be going sightseeing. It is intent on discovering whether there is or was life on Mars. It is happy to trade measurements for mobility", Pillinger says.
Beagle will take soil samples, analyse chemical isotopes and measure atmospheric methane, which could reveal the required evidence.
NASA says that the Rovers "are not trying to detect water per se but are looking at the geology and mineralogy that would indicate the presence of water activity". The Rovers will be able to cover a much wider area, travelling up to 1km per day.
Meanwhile, NASA has stopped work on the first spacecraft to explore the last planet in the solar system to be looked at by man.
The Pluto Kuiper Express, originally scheduled for a 2004 launch to arrive at Pluto in 2014, will be replaced by a new design of spacecraft that will possibly make a delayed mission sometime before 2020.
The mission has lost out to a Europa orbiter to fly to the "water-moon" of Jupiter which has captured the imagination of astrobiologists in their quest to find life in the solar system.
Source: Flight International
