CGRO
CGRO (Compton Gamma-Ray Observatory), one of NASA's Great Observatories, studied the gamma-ray sky using four telescopes that detected different energies. The mission found a class of active galaxies called blazars, mapped the Milky Way’s distribution of a radioactive isotope of aluminum, and hinted at gamma-ray bursts’ cosmological origins, among other discoveries.
past Mission
Type
Space observatory
Launch
April 5, 1991
Wavelength
Gamma rays
Decommissioned
June 4, 2000
![](https://science.nasa.gov/wp-content/uploads/2023/06/0003356.jpg?w=4096&format=jpeg)
NASA's Compton Gamma Ray Observatory just before release from the space shuttle Atlantis on April 7, 1991, during the STS-37 mission. Compton's successful career ended in June 2000 when the observatory reentered Earth's atmosphere.
Credit: NASA/MSFC
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