Kepler—the beloved NASA telescope responsible for discovering 70% of the 3,800 confirmed “alien worlds” to date—officially met its end yesterday. After nearly a decade of exploration, the telescope ran out of fuel and can no longer transmit data or focus on transient objects in space. During its time in flight the Kepler was able to study nearly 150,000 stars simultaneously and could determine exactly which ones were exoplanets. It met several failures in its time in service (rescuing Kepler was never possible because it orbited the sun, not Earth), but persevered longer than many expected. Read more about Kepler’s achievements at Space.com.