Corot will be the first mission capable of detecting rocky planets, several times larger than Earth, around nearby stars (planets outside our Solar System are referred to as 'exoplanets'). It consists of a 30-centimetre space telescope and will be launched later in 2006. Corot will use its telescope to monitor closely the changes in a star's brightness that comes from a planet crossing in front of it. While it is looking at a star, Corot will also be able to detect 'starquakes' that send ripples across a star's surface, altering its brightness. The exact nature of the ripples allows astronomers to calculate the star's precise mass, age and chemical composition. From the ground, the only planets detected around other stars have been giant gaseous worlds (Jupiter-like planets), over 10 times the diameter of the Earth. Not affected by the distorting effects of the atmosphere, Corot will be the first spacecraft capable of finding worlds made of rocks. With Corot, astronomers expect to find between 10-40 of them, together with tens of new gas giants. Corot is a mission by the French national space agency CNES with a major participation by ESA. Today's Programme provides an overview of the satellite and the mission of Corot.