Astronomers have this month trained the world's largest steerable radio telescope on 86 Earth-like planets. The data collected by the telescope will later be analsyed by an estimated one million amateur alien hunters, users of SETI@home, for messages from other civilisations.

Physicist and cosmologist Paul Davies has made an unusual move into the infant discipline of astrobiology. He tells Plus about his interest in the big questions: what is life, how would we recognise aliens - and are they all around us?