The COROT (COnvection ROtation and planetary Transits) spacecraft has opened its protective cover and has gathered its first starlight of the mission. The spacecraft has two primary goals: 1) To detect planets in other stellar systems as they pass in front of their parent stars, blocking some of the light, and 2) To study stellar interiors by detecting the ripples spreading 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.
Presently the spacecraft is undergoing a sensor calibration phase, and the main scientific mission will begin in February. It is designed to be able to detect extrasolar planets smaller than Earth-based telescopes are capable of finding. It is hoped that it will find rocky planets that are just a few times the mass of Earth. Up until now, it has only been possible to find very massive planets, the size of Jupiter or larger.
Earth-based extrasolar planet detectors look for a ‘wobble’ in the star by examining the spectrum of the star’s light for minute changes in the color of the light, an indication that the star is moving toward us (blue-shifted), and then away from us (red-shifted).
COROT and Kepler (to be launched in 2008) will look for planetary transits, where a planet passes between the star and the telescope. It will look for the minute dimming of the star’s light indicating that the star has been partially occluded (blocked) by an intervening object.
In addition, COROT will be looking for ‘ripples’ on the surface of the stars, which will give the scientists information on the composition and behavior of the stars. The SOHO (SOlar & Heliospheric Observatory) spacecraft has been studying our sun since 1995. Now we’ll be able to correlate those observations with observations from other stars.