After just shy of a decade of active service, NASA’s Kepler Space Telescope has ceased operations.

Announcing the end of the telescope’s active life, Thomas Zurbuchen of NASA’s Science Mission Directorate in Washington DC said the telescope, orbiting at 151 million kilometres above Earth, had run out of fuel.

The telescope, launched in March, 2009, was the first piece of custom-built hardware designed to look for exoplanets. It was originally intended to operate for just 3.5 years, but ended up being coaxed to continue for six more.

“As NASA’s first planet-hunting mission, Kepler has wildly exceeded all our expectations and paved the way for our exploration and search for life in the solar system and beyond,” said Zurbuchen.{%recommended 5727%}

“Not only did it show us how many planets could be out there, it sparked an entirely new and robust field of research that has taken the science community by storm. Its discoveries have shed a new light on our place in the universe, and illuminated the tantalising mysteries and possibilities among the stars.”

As eulogies go, it’s a pretty good one. Analyses of Kepler’s discovery suggest that as many as 50% of visible stars are orbited by at least one small, rocky planet in the zone commonly thought to be best suited for the development of life.

The original mission plan called for Kepler to survey 150,000 stars in the constellation Cygnus. Some later technical fixes allowed the craft to switch its focus every three months, allowing it by the end of its life to look at more than half a million.

Data downloaded in the telescope’s final months is still waiting to be analysed, holding out the promise of further fascinating discoveries – some of which, no doubt, will be investigated by Kepler’s successor, the soon to be launched James Webb Space Telescope.