https://www.scientificamerican.com/article/one-search-to-almost-rule-them-all-hundreds-of-hidden-planets-found-in-kepler-data/

Most of the more than 4,000 exoplanets astronomers have found across the past few decades come from NASA’s pioneering Kepler mission, which launched in 2009 and ended in late October 2018. But among Kepler’s cavalcade of data, more planets are still waiting to be found—and a new method just turned up the biggest haul yet from the mission’s second, concluding phase, called K2.

The K2 run from 2014 to 2018 was notable for its unique use of the functionality, or lack thereof, of the Kepler space telescope. Essentially a large tube with a single camera, Kepler relied on four reaction wheels (spinning wheels to orient the spacecraft) to point at specific patches of the sky for days or even weeks on end. Such long stares were beneficial for its primary planet-finding technique, known as the transit method, which detects worlds by watching for dips in a star’s light caused by an orbiting planet’s passage in front of it. But when two of Kepler’s reaction wheels failed, one in 2012 and another in 2013, mission planners came up with an ingenious method of using the pressure of the solar wind to act as a makeshift third wheel, allowing observations to continue, albeit with some limitations.