The
Astronomy Café -- contains links to many astronomical
resource sites and answers to thousands of questions about astronomy
and space asked by web surfers are nicely categorized
CDS
Data System -- huge resource site, astronomical catalogs
galore
e-Prints in
Astronomy & Physics -- Automated e-print archives in physics,
mathematics, etc.; normally requires postscript printer to print
articles or ghostscript to read them on-line.
Jet Propulsion
Laboratory -- a wealth of information about unmanned planetary
missions and astronomy and space in general; extrasolar planet and
other links; asteroids and comet impact hazards are nicely covered
The Nine Planets -- a wealth of information about the
planets and their satellites with photographs
Sky and
Telescope -- magazine's webpage excellent for amateur
astronomers and for anyone interested in the latest discoveries
in astronomy