Your chance to spot an alien world

Fancy yourself as a planet hunter? Who knows, you could be the first to spot the telltale signature of an earth-like world orbiting a distant star.

That's the tantalising prospect scientists at NASA and Oxford University are offering to those willing to wade through the mountain of data being generated by the Kepler Space Observatory.

Kepler has been sitting out there in deep space quietly photographing a patch of sky between Cygnus and Lyra every 30 seconds or so for 18 months. That's generated a colossal amount of data - and while the computer algorithms researchers are using to process the images are good at spotting huge Jupiter-like gas giants, they're less reliable when it comes to teasing out the signal of smaller planets 'lost' in the background noise.

For that you need the subtle pattern processing powers of a much more sophisticated computer - the human brain. And that's where you come in.

"There's a good chance that some of these alien worlds are being lost in the noisy background data from Kepler" says physicist Dr Chris Linott from Oxford University's Department of Physics. "What we're hoping is that the human eye might be able to spot these lost worlds, rescuing planets that automatic techniques have missed".

The team has built a website, Planethunters.org, that allows anyone to sift through the Kepler data on individual stars one by one, and to submit likely candidates for hidden planets.

When a planet orbiting a distant star passes in front of it - a transit - the light from that star dims briefly before picking up again. It's this telltale dip in luminosity researchers want people to highlight in the data. Then they can go back and confirm the discovery.

"We've found from previous projects that people, armchair astronomers, are very good at sifting this sort of data," says Arfon Smith who helped design the website, "but one of our users spotting an earthlike planet in another star system would be a fantastic achievement."

It's an exciting idea, and who knows, perhaps a Today programme listener will be the first to spot a planet orbiting a distant star.