🛰️ Mission
Fermi Gamma-ray Space Telescope
Sweeps the whole sky for gamma rays, every three hours.
- Launched
- 11 June 2008, 18 years ago
- Working for
- 18 years so far
- Built by
- NASA
- Sees
- Gamma rays
- Where it is
- Circling Earth about 550 km up, turning as it goes so it sees everything twice a day
- Best known for
- Found the Fermi bubbles: two enormous lobes of gamma rays blown out above and below the middle of our galaxy, which nobody had suspected were there
Did you know?
- It launched as GLAST and was renamed four months later after Enrico Fermi, who first worked out how cosmic rays get their energy.
- Gamma rays are the most energetic light there is, and no mirror can focus them. It works out where each one came from by tracking the pair of particles it makes on the way in.
What it showed us
The Milky Way
Our home galaxy. The Sun is one of its hundreds of billions of stars.
Crab Nebula
The leftovers of a star that exploded almost 1,000 years ago.
Centaurus A
A giant black hole at the heart of the closest active galaxy.
More NASA photos of Fermi Gamma-ray Space TelescopeStraight from NASA’s image library, in the app
Explore more
All of missions
Hubble Space Telescope
Thirty-six years above the weather, and still working.
James Webb Space Telescope
A golden mirror that sees the first galaxies in infrared.
Chandra X-ray Observatory
The telescope that shows what is hot and violent.
Spitzer Space Telescope
Sixteen years of infrared, through dust that hides everything else.
Kepler
Stared at one patch of sky and found thousands of planets.
TESS
Kepler’s successor, watching the whole sky for planets.