Spacewatch: Nasa planet hunter will target the rock zone

Using the TESS satellite, now at the Kennedy Space Centre, the agency is to study 200,000 stars in a quest for habitable planets

Nasa's next planet hunting mission has arrived at the Kennedy Space Centre, in Florida, for final checks ahead of its April launch. The Transiting Exoplanet Survey Satellite (TESS) will spend at least two years studying more than 200,000 nearby stars and looking for planets. The mission is expected to discover thousands of previously unknown worlds by detecting the small drops in light which occur when each planet passes across the face of its parent star.

This approach, known as the transit method, was employed to great effect by Kepler, a Nasa mission which has detected, so far, more than 2,500 confirmed planets around other stars.