Issue 13 - April 2014
Edited by Ingolf Heinrichsen and Nick Gautier Planet Bonanza, 715 New Worlds On February 26, NASA's Kepler mission announced the discovery of 715 new planets. These newly verified worlds orbit 305 stars, revealing multiple-planet systems much like our own solar system. A research team co-led by Jack Lissauer (NASA's Ames Research Center) used a new technique called verification by multiplicity. This technique relies on the fact that false positive planet indications not associated with Kepler target stars, mainly eclipsing binary stars in the background of a Kepler target star, are not very densely distributed on the sky. Therefore, if a target star shows multiple planet candidates it is very unlikely that more than one is a false positive. The normal follow-up work that Kepler does for planet candidates then can eliminate most of the remaining possibilities for false positives, producing a very clean set of multiple planet systems. "We've now developed a process to verify multiple planet candidates in bulk to deliver planets wholesale, and have used it to unveil a veritable bonanza of new worlds," says Lissauer. Nearly 95 percent of these planets are smaller than Neptune, which is almost four times the size of Earth. This discovery marks a significant increase in the number of known small-size planets more akin to Earth than previously identified exoplanets, which are planets outside our solar system. Four of these new planets are less than 2.5 times the size of Earth and orbit in their sun's habitable zone. The full story can be found here. The two papers can be found here: Lissauer et al. and Rowe et al. Kepler Marks Five Years in Space NASA's Kepler Space Telescope celebrated its five-year launch anniversary on March 6. In five years of operation, Kepler's data have revealed more than 3,600 candidate planets and confirmed 961 of those candidates. Because of Kepler, we now know that most stars have planets, Earth-size planets are common, and planets quite unlike those in our solar system exist. In August 2013, the mission ended its science observations after a second faulty reaction wheel affected the telescope's ability to point precisely. The mission may be able to operate in a different mode and continue to do science. New mission proposals will be considered for funding by NASA in the 2014 Astrophysics Senior Review of Operating Missions. You can read more about Kepler’s anniversary here. Kepler Mission Manager Update: Loss of a Science Module During a scheduled test, we were very encouraged to see that the spacecraft operated using the fine-guidance sensors mounted on the focal plane. Having now brought the data back from the spacecraft, we have found that during the test, one of the science detector modules failed. The Kepler focal plane is made up of a mosaic of 21 science detector modules. Four years ago, less than a year into the mission, one of the modules (Module 3) failed. An extensive review was unable to determine a specific cause, but was able to isolate the problem to a part failure in the circuitry powering that module. The new failure, Module 7, appears to be another occurrence of the same, or a very similar, problem. We have only begun our assessment of the problem, but it is likely to be another isolated occurrence of a part failure. The remaining 19 modules still allow for a very large view of the sky, and the target resources that would have fallen on Module 7 have been reassigned to the remaining modules. At this time, it does not appear that this will have any impact on future use of the telescope. National Space Club Honors Kepler's Planet Hunters The Kepler Team received the National Space Club’s preeminent award, the Dr. Robert H. Goddard Memorial Trophy. The citation reads: Kepler has revolutionized exoplanet science and stellar astrophysics by expanding the galactic census of exoplanet candidates and fundamentally altering our understanding of our place in the galaxy. This honor is afforded Kepler in recognition of their significant contribution to U.S. leadership in the field of rocketry and astronautics.