According to the website Spaceflight Now, a Russian Soyuz 2-1b rocket with the European COROT space observatory launched at 1423 GMT (9:23 a.m. EST) from Baikonur Cosmodrome, Kazakhstan. The French-led COROT mission will look for rocky planets around other stars.

Flying high above the Earth's atmosphere, the Convection Rotation and planetary Transits (COROT) satellite [[image] will use a different technique better suited to finding smaller worlds. Called the "transit" technique [image], it will detect extrasolar planets by measuring the dip in starlight their passage creates as they glide across the face of their parent stars.

COROT's 27 centimeter (10.6 inch) lens will monitor the brightness of the stars, looking for the slight dip in starlight caused by the planet's passage. COROT will be able to monitor hundreds of thousands of stars simultaneously and will turn its unblinking eye toward different parts of the sky for 150 days at a time. COROT is expected to find between 10 to 40 rocky worlds over the course of its two and a half year mission, along with tens of new gas giant planets.

As it's observing a star for signs of a planet's passage, COROT will also watch for "starquakes," acoustical waves generated deep inside stars which ripple across a star's surface, altering its brightness. This information can be used to calculate a star's precise mass, age and chemical composition.

In 2008, NASA will launch Kepler, a space telescope that works in the same way as COROT, but which will be able to detect the first Earth-sized planets in similar orbits to our own world.