But the innovative spacecraft enjoyed an illustrious career, discovering as many as 2,600 planets and inspiring new fields of research, NASA said. "Its discoveries have shed a new light on our place in the universe, and illuminated the tantalizing mysteries and possibilities among the stars", said Zurbuchen.
The Kepler space telescope will be retired after running out of fuel nine years after its initial launch, the space agency announced Tuesday.
"Around every star in the galaxy, we're confident now that there's probably at least one planet - so more planets than stars without a doubt and that's something that Kepler has shown us", he said. "Now we know because of the Kepler Space Telescope and its science mission that planets are more common than stars in our galaxy".
The distinction helped scientists zero in on potential Earth-like planets and better the odds of finding conditions which could support life.
"Because of Kepler, we know that planets are an incredibly diverse set of objects, much more diverse than we observe in our own solar system", Hertz said. TESS is created to survey about 200,000 stars across a wide stretch of sky in our celestial neighborhood, and identify prospects for further study.
"We know the spacecraft's retirement isn't the end of Kepler's discoveries", said Jessie Dotson, Kepler's project scientist at NASA's Ames Research Centre in California's Silicon Valley.
Launched on March 6, 2009, Kepler breathed its last yesterday (Oct. 30) when its mission ended due to a lack of fuel needed for further science operations, according to NASA.
"While this may be a sad event, we are by no means unhappy with the performance of this marvellous machine", NASA project system engineer Charlie Sobeck said.
It's the pioneering telescope which, for those of us on Earth, filled the galaxy with planets.. NASA has made a decision to retire the spacecraft, letting it continue its current orbit around the sun for eternity.
For years, Kepler stared at a fixed area of the sky bridging the constellations Lyra and Cygnus to monitor about 150,000 stars for signs of planets. However, while Kepler spent its prime mission looking at a single, very small region of the sky, TESS is performing an all-sky survey focused on the nearest and brightest stars.
He said Kepler showed mankind how many planets might be out there. "Now we know there are billions of planets that are rocky like the Earth and are orbiting their stars in the habitable zone, or the Goldilocks zone, where their temperatures might be conducive to water on the surface".
Mr Borucki described his favourite exoplanet, named Kepler 22B, which was first spotted by the telescope in 2009 and is located more than 600 light years from Earth. "There were definitely challenges, but Kepler had an extremely talented team of scientists and engineers who overcame them". Launched in April, TESS will build on Kepler's planet-hunting legacy by searching for exoplanets around almost 200,000 of the brightest and nearest stars to Earth.
Four years into the mission, the main goals had been met, but mechanical failures put a sudden end to future observations.
NASA's Ames Research Center manages the Kepler and K2 missions for NASA's Science Mission Directorate. As of October 29, Kepler had detected 2,681 exoplanets, with an additional 2,899 exoplanet candidates awaiting confirmation, said Jessie Dotson, Kepler project scientist at NASA Ames.