Jumpy stars slow hunt for other Earths; NASA mission looks for extra time to battle stellar noise.
Source: Ron Cowen, Nature
Excerpt: The Kepler spacecraft has hit an unexpected obstacle as it patiently watches the heavens for exoplanets: too many rowdy young stars. The orbiting probe detects small dips in the brightness of a star that occur when a planet crosses its face. But an analysis …has found that the stars themselves flicker more than predicted, with the largest number varying twice as much as the Sun. That makes it harder to detect Earth-sized bodies. …the analysis suggests that Kepler will need more than double its planned mission life of three-and-a-half years to achieve its main goal of determining how common Earth-like planets are in the Milky Way.... "We need an extended mission because the detection of Earth-sized planets hangs in the balance," says Geoff Marcy ... a member of the Kepler team....