A space observatory, formerly named GLAST, devoted to the study of
→ gamma rays
emitted from astrophysical objects.
Developed by NASA in collaboration with the U.S. Department of Energy,
along with important contributions from academic institutions and
partners in France, Germany, Italy, Japan, Sweden, and the United
States, Fermi was launched on June 11, 2008.
The main instrument, the Large Area Telescope (LAT), is an imaging
→ camera covering the
energy range from about 20 → MeV to more than 300
→ GeV. Such gamma rays
are emitted only in the most extreme conditions, by particles moving
very nearly at the → speed of light.
The LAT’s → field of view covers
about 20% of the sky at any time, and it scans continuously, covering
the whole sky every three hours.
Another instrument, the Gamma-ray Burst Monitor (GBM) has a field of view several times
larger than the LAT and provides → spectral coverage
of → gamma-ray burst
that extends from the lower limit of the LAT down to 10 → keV.
See also: → Fermi; → gamma ray;
→ space; → telescope.
