If another advanced civilisation in the Milky Way is the proverbial needle, a group of researchers has suggested how we should narrow our search for it in the galactic haystack.

At a meeting of the American Astronomical Society in St Louis, Missouri, US, on Wednesday, Richard Conn Henry of Johns Hopkins University and colleagues proposed limiting the search for extra-terrestrial intelligence (SETI) to the ecliptic - the plane in which our solar system's planets orbit.

SETI begins with the...