The following links will take you to web sites which are especially useful, informative, and entertaining.
The
Nature of the Universe Great Debate in 1998
The
Great Shapley-Curtis Debate of 1920 on the Scale of the Universe
Astronomy
Picture of the Day Archive
Hubble
Space Telescope Images
Color
Photographs from the Anglo-Australian Observatory
National
Radio Astronomy Observatory: Very Large Array
European Southern
Observatory: Very Large Telescope (Optical)
Advanced
X-ray Telescope Facility (AXAF) Science Center
Laser Gravitational-wave
Interferometer Observatory (LIGO)
Sudbury
Neutrino Observatory
STScI
Digitized Sky Survey: The Whole Sky, gif or fits
Virtual
Trips to Black Holes and Neutron Stars (MPEG movies)
Colliding
Galaxies Movies
The MACHO
Dark Matter Search Project
Center
for Particle Astrophysics: "Dark Matter" hypertext
Very useful but less entertaining
Los
Alamos Preprint Server ("astro-ph")
AstroWeb
NASA
Astrophysics Data System ABSTRACT SERVICE
Harvard's
Astronomy 45 Classnotes
Celestial
Coordinates and all that from 8.13-4 (PDF)
Less useful but more entertaining
MIThenge
The
Milky Way at 7 different wavelengths FREE
poster
COBE
Legacy: FREE poster