This image from NASA's Galaxy Evolution Explorer (GALEX) shows Messier 94, also known as NGC 4736, in ultraviolet light. It is located 17 million light-years away in the constellation Canes Venatici. Image credit: NASA/JPL-Caltech
(Phys.org) —NASA has turned off its Galaxy Evolution Explorer (GALEX) after a decade of operations in which the venerable space telescope used its ultraviolet vision to study hundreds of millions of galaxies across 10 billion years of cosmic time.
"GALEX is a remarkable accomplishment," said Jeff Hayes, NASA's GALEX program executive in Washington. "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."
Operators at Orbital Sciences Corporation in Dulles, Va., sent the signal to decommission GALEX at 12:09 p.m. PDT (3:09 p.m. EDT) Friday, June 28. The spacecraft will remain in orbit for at least 65 years, then fall to Earth and burn up upon re-entering the atmosphere. GALEX met its prime objectives and the mission was extended three times before being cancelled.
Highlights from the mission's decade of sky scans include:
— Discovering a gargantuan, comet-like tail behind a speeding star called Mira.
— Catching a black hole "red-handed" as it munched on a star.
— Finding giant rings of new stars around old, dead galaxies.
— Independently confirming the nature of dark energy.
— Discovering a missing link in galaxy evolution—the teenage galaxies transitioning from young to old.
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