Kepler Planet Searcher Launched

Astronomers first discovered a planet outside our solar system in 1994 and have since identified 340 of them.

In fact, last month, French scientists announced the discovery of Exo-7b, the second planet circling the Exo-7 star about 390 light years away. The planet was discovered by the Corot, an Earth-orbiting telescope that France launched six years ago.

Yesterday, NASA launched "Kepler". This instrument will simultaneously analyze 100,000 stars seeking out new planets. It detects planets by measuring the small light shifts when a planet orbits its sun - like picking up the light change from a mosquito in front of a headlight.

(source)