The Compton Gamma Ray Observatory
			
		
		
			Credit:
		
		
			The 
Compton Gamma Ray Observatory (CGRO) was the most massive instrument
ever 
launched by a NASA Space Shuttle and continues to 
revolutionize gamma-ray astronomy.  This orbiting observatory sees the sky in 
gamma-ray photons - light so blue humans can't see it.  These photons
are blocked by the Earth's atmosphere from reaching the Earth's surface.  
Results from CGRO
have shown the entire universe to be a violent and rapidly changing place
- when viewed in gamma-rays.  Astronomers using CGRO data continue to 
make monumental discoveries, including 
showing that mysterious flashes
of gamma-rays are much more powerful than previously imagined,
 
discovery of a whole new class of QSO, and 
discovery of objects so 
strange that astronomers can't yet figure out what they are.