The $600 million mission's future is in doubt after the second of the observatory's four orientation-maintaining reaction wheels failed in May 2013. (Kepler needs at least three working reaction wheels to stay locked onto its 150,000-plus target stars.)
Whether or not Kepler can continue hunting for alien worlds, the mission has been a spectacular success, researchers say, flagging more than 2,700 potential alien planets thus far. And more discoveries will keep rolling in for years to come as team members pore through the spacecraft's data.
Here are some of Kepler's greatest finds to date.
FIRST STOP: A Rocky Exo-world
NEXT: 'Tatooine Planet' with twin Suns
NEXT: Alien Planet Smaller Than Earth
NEXT: A Truly Habitable World?
NEXT: The Smallest Exoplanet
NEXT: Potentially Habitable Water Worlds
NEXT: The Exoplanet Picture