Life in the Cosmos

Are there living things elsewhere in the universe? Barring the arrival of the flying saucers over the capital cities of the world, we'll have to try to answer this tantalising question using the same tactics employed for any of the big scientific questions, a bit like the assembly of a very large jigsaw puzzle of an unusual character. We have lots of little, detailed pieces for some bits of the picture but there are other, big sections we have few or no pieces for and we're going to have to go out to try to find them. Sometimes we'll come back with a handful of pieces that turn out to be wrong, or to belong in a different jigsaw. We're not really sure of the ultimate size or shape of the picture and there may be entire sections we're not yet aware of, whose existence will only become clear because they're needed to fit into the bits we've completed in detail. At the present time the sizes of the pieces also vary enormously: some parts of the picture are represented in detail by lots of teensy pieces, other bits are like the big, chunky pieces of a toddler's jigsaw, drawing crude, unsubtle shapes in primary colours. We'd love to take the jig saw to those bits and render them more finely, in particular to see if there are big new, unsuspected bits that border them. People will spend their entire scientific careers filling in wee bits of the jigsaw and they may even turn out not to be so important - they were smaller bits, making a smaller part of the picture, than we thought at the time.

There might never come a time when the jigsaw is definitively finished.

Astronomers are working very hard at the extraterrestrial life jigsaw right now, on several different fronts, and there are stories in the media all the time. So in the last couple of days we have learnt that there has been liquid water on Mars in "recent" times; and we've heard that one quarter of observed Sun-like stars harbors a close-in terrestrial-mass planet (these links are to the American journal Science - you can read the abstracts but you'll have to be inside an organisation with a subscription to go further).

The presentation of these stories in the mass media often causes problems, however. "Scientists might possibly have found a new Earthlike planet" is not nearly as attention-grabbing a headline as "At last, an Earthlike planet that could harbour life!" The widely reported discovery of such a planet a couple of weeks ago has turned out to be more tentative than most reports suggested, with an inevitable backlash as foolish as the initial hype. The mystery of the disappearing planet in the Guardian deals really well with this, highlighting the perennial clash between the demands of journalism and the long, painstaking process of completing the jigsaw puzzle.

How can you find out what's behind the headlines? Come to our courses! We'll mention the caveats and uncertainties alongside the exciting results. There's time to ask questions and we're aiming to explore the ideas, not propagandise. My starting point here is Astronomy - and we do have a "Life in the Cosmos" course after Xmas - but these comments apply to any of our science courses, and "explore the ideas", in science or otherwise, is what universities are for.

It's too beautiful a day to sit in the house. But before I stop, here's a very different, I think wonderful sort of science communication: "Dance your PhD 2010".