Planetary Systems: Extrasolar Planets
An extrasolar planet, or exoplanet, is a planet beyond the Solar System, orbiting around another star. As of December 2008, 333 exoplanets are listed in the Extrasolar Planets Encyclopaedia. The vast majority have been detected through radial velocity observations and other indirect methods rather than actual imaging. Most exoplanets are massive gas giant planets thought to resemble Jupiter, but this is a selection effect due to limitations in detection technology. The forthcoming NASA Kepler Mission will search for exoplanets using a completely different technique: planetary transits. It is estimated that at least 10% of sun-like stars have planets, and the true proportion may be much higher. The discovery of extrasolar planets sharpens the question of whether some might support extraterrestrial life. Currently, Gliese 581d, the third planet of the red dwarf star Gliese 581 (approximately 20 light years from Earth), appears to be the best example yet discovered of a possible terrestrial exoplanet that orbits close to the habitable zone surrounding its star.
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SIM PlanetQuest
SIM (Space Interferometry Mission), scheduled for launch within the next decade, will be the most powerful planet-hunting space telescope ever devised. Using two separated mirrors and combining their...
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A Little Telescope Goes a Long Way
PASADENA, CA (Feb. 9, 2010) – NASA astronomers have successfully demonstrated that a David of a telescope can tackle Goliath-size questions in the quest to study Earth-like planets around other...
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- NASA's Spitzer Spots Clump of Swirling Planetary Material
- Simulation suggests rocky exoplanet has bizarre atmosphere
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