f556c24b__04_22_2004____Background_Info__2004
[1990] Help resolve the mystery of the nature of quasars. Ground-based telescopes could not see the host galaxies of quasars. [2004] 
Confirmed that quasars reside in galaxies, and also revealed that many of these galaxies are merging with other galaxies.
HubbleSite - NewsCenter - The Lure of the Rings (04/22/2004) - Background Info
2004