COROT- Europe’s planet-seeker
This artist's view shows the COROT satellite, consisting of a 27-centimetre space telescope. A mission led by CNES with ESA participation, it was launched in December 2006.
COROT uses its telescope to monitor closely the changes in a star’s brightness that comes from a planet crossing in front of it.
When looking at stars, COROT is able to detect ‘starquakes’, acoustical waves generated deep inside a star that send ripples across a star’s surface, altering its brightness. The exact nature of the ripples can allow astronomers to calculate the star's mass, age and even chemical composition.
Credits: CNES - D. Ducros
One of the methods for detecting exoplanets is to look for the drop in brightness they cause when they pass in front of their parent star. Such a celestial alignment is known as a planetary transit.
From Earth, both Mercury and Venus occasionally pass across the front of the Sun. When they do, they look like tiny black dots passing across the bright surface.
Such transits block a tiny fraction of the light that COROT is able to detect.