Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2000 April 8
See Explanation.  Clicking on the picture will download 
 the highest resolution version available.

Compton Observatory In Orbit
Credit STS-37 Crew, NASA

Explanation: Nine years ago the massive Compton Gamma Ray Observatory was deployed in low earth orbit. Sparkling interior reflections and the bright limb of the Earth are visible in this 1991 window view of Compton's release by the crew of the Space Shuttle Atlantis. Lofted above the protective atmosphere, Compton's instruments could explore the extreme high-energy Universe in gamma rays, photons with 100,000 times or more the energy of visible light. The premier gamma-ray observatory far exceeded expectations for a two- to five-year mission, but a recent gyroscope failure has prompted NASA to decide to steer the satellite safely back into the atmosphere. Compton's lasting legacy of discovery will include the detection of more than 400 celestial gamma-ray sources, 10 times more than were previously known; and more than 2,500 gamma-ray bursts.

Tomorrow's picture: Pluto and Charon

< | Archive | Index | Search | Calendar | Glossary | Education | About APOD | >

Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (USRA)
NASA Technical Rep.: Jay Norris. Specific rights apply.
A service of: LHEA at NASA/ GSFC
& Michigan Tech. U.