NASA’s Deep Impact spacecraft is aiming its largest telescope at five stars in a search for alien (exosolar) planets as it enters its extended mission, called Epoxi. Deep Impact made history when the mission team directed an impactor from the spacecraft into comet Tempel 1 on July 4, 2005. NASA recently extended the mission, redirecting the spacecraft for a flyby of comet Hartley 2 on Oct. 11, 2010. As it cruises toward the comet, Deep Impact will observe five nearby stars with “transiting exosolar planets,” so named because the planet transits, or passes in front of, its star. The Epoxi team, led by University of Maryland astronomer Michael A’Hearn, directed the spacecraft to begin these observations January 22nd. The planets were discovered earlier and are giant planets with massive atmospheres, like Jupiter in our solar system. They orbit their stars much closer than Earth does the sun, so they are hot and belong to the class of exosolar planets nicknamed “Hot Jupiters.” More than 200 exosolar planets have been discovered to date. Most of these are detected indirectly, by the gravitational pull they exert on their parent star. Directly observing exosolar planets by detecting the light reflected from them is very difficult, because a star’s brilliance obscures light coming from any planets orbiting it.
Deep Impact Obtains Epoxi
NASA’s Deep Impact spacecraft is aiming its largest telescope at five stars in a search for alien (exosolar) planets as it enters its extended mission, called Epoxi. Deep Impact made history when the mission team directed an impactor from the spacecraft into comet Tempel 1 on July 4, 2005. NASA recently extended the mission, redirecting the spacecraft for a flyby of comet Hartley 2 on Oct. 11, 2010. As it cruises toward the comet, Deep Impact will observe five nearby stars with “transiting exosolar planets,” so named because the planet transits, or passes in front of, its star. The Epoxi team, led by University of Maryland astronomer Michael A’Hearn, directed the spacecraft to begin these observations January 22nd. The planets were discovered earlier and are giant planets with massive atmospheres, like Jupiter in our solar system. They orbit their stars much closer than Earth does the sun, so they are hot and belong to the class of exosolar planets nicknamed “Hot Jupiters.” More than 200 exosolar planets have been discovered to date. Most of these are detected indirectly, by the gravitational pull they exert on their parent star. Directly observing exosolar planets by detecting the light reflected from them is very difficult, because a star’s brilliance obscures light coming from any planets orbiting it.
