After nearly four years mapping the "hidden universe," the largest infrared telescope ever launched into space has reached the end of its life, European Space Agency officials say.
The $1.4 billion Herschel Space Observatory has exhausted the vital supply of liquid helium coolant that allowed it make the most sensitive and detailed observations of the cosmos in infrared light, ESA officials announced Monday (April 29).
The infrared space telescope's official end was recorded by a ground station in Australia, which recorded an increase in temperature for all of the spacecraft's instruments during the telescope's daily communications session. It began its mission in May 2009. [Amazing Photos from the Herschel Space Telescope]
"Herschel has offered us a new view of the hitherto hidden universe, pointing us to a previously unseen process of star birth and galaxy formation, and allowing us to trace water through the universe from molecular clouds to newborn stars and their planet-forming discs and belts of comets," ESA's Herschel project scientist Göran Pilbratt said in a statement.