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.

Two of the most fundamental questions asked by people are how life emerged on the Earth, and whether we are alone in the cosmos. These deeply important questions form the core of a new kind of science, one that recently has been rapidly gathering momentum: astrobiology. Lewis Dartnell explains.

Well educated aliens

Mathematics tackles an eternal question

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?