Great news, Kepler enthusiasts. The once-failing spacecraft is back, thanks to some clever engineers and astronomers who figured out how to work around its dead positioning wheels. Although all seemed lost earlier this year, when two out of four of its gyroscope wheels failed (it requires a total of three to work correctly), NASA started working on new ideas to keep it in business. Fortunately, their plan seems to be working, and Kepler has just spotted its first exoplanet since it began malfunctioning.
Before we get too excited, though, this new planet that Kepler spotted isn’t exactly new. It was previously spotted by the WASP telescope. However, Kepler finding it (again) means that we know the space telescope still works. Although Kepler lost its positioning capabilities when its wheels failed, making it unstable, NASA and a team of engineers figured out how to use the Sun to position the spacecraft. Solar panels power Kepler, and the pressure of photons on these panels keep it stable enough to get back to studying the skies.
Unfortunately, this new way of positioning the spacecraft comes with a downside. For its observations, Kepler’s position relative to the Sun must be specific and it can only hold this position for 75 days. This is not enough time to determine if a potential planet, is in fact, a planet. Kepler finds planets by studying light patterns that indicate transiting, which happens when a planet moves in front of a star, changing the intensity of the light coming from that star from the spacecraft’s point of view. Kepler needs to witness this at least three times for planet confirmation, which generally requires at least three years of observations.
However, Kepler is still important enough for NASA to ask for two more years of funding for the mission. Although Kepler cannot confirm planets now, it can still spot new stars and hunt for planets around them. If funding comes through, Kepler has already been given its first new mission: to observe over 100,000 young stars.
Via New Scientist