Extrasolar planet

An extrasolar planet, or exoplanet, is a planet outside the Solar System. As of December 6, 2010, astronomers have announced the detection of 506 such planets, with hundreds more planet candidates awaiting to be confirmed by more detailed investigations.The vast majority have been detected through radial velocity observations and other indirect methods rather than actual imaging. Most are giant planets thought to resemble Jupiter; this partly reflects a sampling bias in that more massive planets are easier to observe with current technology. Several relatively lightweight exoplanets, only a few times more massive than Earth, have also been detected and projections suggest that these will eventually be found to outnumber giant planets.