An artist’s depiction of the Kepler Space Telescope and exoplanets circling distant stars. Image Credit: NASA
Numerous planetary systems, including a world just discovered by citizen scientists, are visible in the final images taken by NASA’s Kepler telescope on Sept. 25, 2018, just before it ran out of fuel after operating for nine-and-a-half years.
Kepler’s final full field-of-view image, taken on Sept. 25, 2018. Photo Credit: NASA/Ames Research Center
Between Kepler’s “first light” image of star-filled regions in the constellations of Cygnus and Lyra, taken in 2009, and this “last light” one focused in the direction of the constellation Aquarius, the telescope discovered over 2,600 exoplanets, including the TRAPPIST-1 system of seven closely-packed terrestrial worlds, three of which are located in the parent star’s habitable zone.
Kepler used the transit method to locate planets, which involves searching for regular dips in light caused by a planet transiting, or passing in front of, its parent star. It monitored all stars in its field of view continuously so as to assure no transits were missed.
In May 2013, when the second of Kepler’s four reaction wheels failed, its four-year mission of constantly monitoring 150,000 stars ended. A year later, the telescope was ...