COROT- Europe’s planet-seeker
The search for planets far beyond our Solar System entered a new era on 27 December 2006 with the launch of Europe’s COROT spacecraft. Carried into orbit by a new version of the Soyuz rocket, COROT lifted off from Baikonur cosmodrome in Kazakhstan at 15:23 CET. 50 minutes later the 630-kg satellite was placed into a perfect polar orbit, 900 km above the Earth.
Since then, COROT’s 30-cm telescope and highly sensitive camera have been used to study ‘starquakes’ and search for new worlds. The spacecraft does this by collecting the faint light from 120,000 stars and sending it to a special two-part camera.
One half of the camera is designed to discover distant planets. This is done by recording tiny drops in a star’s brightness as a planet moves in front of it. Many of the objects COROT has found are 'hot-Jupiters' – giant planets very close to their stars. However, it has also detected a small number of ‘super-Earths’. These rocky worlds are only a a few times larger than Earth. COROT-7b – less than twice Earth’s diameter - was the smallest exoplanet ever found.
The other half of the camera is able to detect tiny changes in a star’s light output caused by sound waves rippling across the surface. These are like earthquake waves on Earth, and they enable scientists to learn a lot about conditions inside each star. Similar studies of the Sun have already been made with ESA’s SOHO spacecraft.