Space - our favourite frontier

Exploring space is an expensive business, but robots are cheaper (and more expendable) than sending astronauts. European scientists understandably want to build on their success with the Mars Express mission - currently orbiting our planetary neighbour successfully - to land a robotic rover on the surface of the Red Planet. At £350m, it is expensive. But, in theory, this instrument could help to answer one of the most intriguing questions to haunt humanity (and, for that matter, Hollywood): are we alone?

Exploring space is an expensive business, but robots are cheaper (and more expendable) than sending astronauts. European scientists understandably want to build on their success with the Mars Express mission - currently orbiting our planetary neighbour successfully - to land a robotic rover on the surface of the Red Planet. At £350m, it is expensive. But, in theory, this instrument could help to answer one of the most intriguing questions to haunt humanity (and, for that matter, Hollywood): are we alone?

Over the past 10 years we have seen accumulating evidence suggesting that simple life forms may have evolved on Mars at some point in the past four billion years. Britain's ill-fated Beagle-2 space probe had the necessary instruments to answer that question, but it was, famously, lost on its descent to Mars in 2003. Now the Aurora rover, due to land in 2013, could provide us with tantalising proof of extra-terrestrial life. If it did, then £350m might seem cheap at the price.