How are astronomers able to locate and determine somewhat detailed information about planets outside our solar system? Fairly simple terminology that even I can understand would be great.

star_gazer

The 32 new planets were found over the past five years using an instrument called a spectrograph at the European Southern Observatory in La Silla, Chile. Known as HARPS, for High Accuracy Radial velocity Planetary Searcher, the spectrograph detects wobbles in a star's orbit caused by the pull of an unseen exoplanet. The HARPS team selected stars like our sun, as well as lower-mass dwarf stars, to watch for wobbles. Red dwarf stars were targets because they are dimmer, low-mass stars, which makes it easier to detect wobbles from low-mass satellite planets, said team member Nuno Santos, of the University of Porto, Portugal. http://news.nationalgeographic.com/news/2009/10/091019-32-new-planets-found.html So, its all about the wobble. Mar 07 10, 6:03 PM