NASA Switches Off Space Telescope GALEX After 10 Years of Research

NASA turned off the Galaxy Evolution Explorer (GALEX) on Friday after a decade of using its vision to study hundreds of millions of galaxies across 10 billion years of cosmic time.

The signal to decommission the space telescope was sent at 3:09 p.m. EDT after three mission extensions by the space agency. The spacecraft will remain in orbit for at least 65 years, accoridng to scientists, before falling toward Earth, at which point it will disintegrate during its journey through the planet's atmosphere. 

"GALEX is a remarkable accomplishment," Jeff Hayes, NASA's GALEX program executive in Washington, said in a statement. "This small Explorer mission has mapped and studied galaxies in the ultraviolet, light we cannot see with our own eyes, across most of the sky."

Sent to map the history of galaxy and star formation in the universe, highlights from the mission's decade of sky scans include the discovery of a massive comet-like tail behind a speeding star called Mira and catching a black hole on camera as it devoured a star.

Other significant observations were finding giant rings of new stars around old, dead galaxies and independently confirming the nature of dark energy. GALEX was also the one to discover a missing link in galaxy evolution - teenage galaxies transitioning from young to old.

In addition to these findings, the space telescope provided new evidence for the "nurture" theory of galaxy evolution, which states that the galaxies first described by Hubble - the elegant spiral and ball shaped elliptical galaxies - are evolutionarily linked.

In 2012, NASA loaned GALEX to Caltech in a first-of-a-kind move for space agency. Caltech then used private funds to continue operating the satellite while NASA retained ownership. Since then, investigators from around the world used the space telescope to examine everything from neighboring stars to to hundreds of thousands of galaxies 5 billion light-years away.

During its final year of operation, the telescope scanned large patches of sky, including the bustling center of our Milky Way, and spent time photographing supernovae. GALEX also spent time monitoring how objects, such as the centers of active galaxies, change over time and searching the heavens for massive, feeding black holes and shock waves from early supernova explosions.

With so much data to analyze, GALEX will continue offering discoveries long after it was switched off, according to scientists.

"GALEX, the mission, may be over, but its science discoveries will keep on going," said Kerry Erickson, the mission's project manager at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, Calif.