NASA has officially retired the Kepler Space Telescope today, after it finally ran out of the fuel needed for further science operations. It is truly the end of an era.



Before Kepler launched in 2009, we did not know if exoplanets were common or incredibly rare. Kepler single-handedly proved that our galaxy is teeming with planets—discovering over 2,600 confirmed worlds and showing us that there are likely more planets than stars in the Milky Way. It profoundly shifted our place in the cosmos, revealing a universe rich with potential habitats. It goes down in history as one of the most successful scientific instruments ever built.