Astronomy Resources
NASA
Google Sky
Space News
Space Weather
Hubble Space Telescope
Astrobiology.com
New General Catalogue
SETI - Center for the Study of Life in the Universe
Arecibo - National Astronomy & Ionosphere Center
Skyview - NASA's virtual telescope.
Google Earth - Explore far-away galaxies, nebulae, and more. Start with the beginner tour to see the highlights or browse on your own to take http://www.wpo.net/galaxieso see imagery from the Hubble Space Telescope, hear about the lifecycle of a star, or even view the constellations.
Celestial Sphere - Very impressive online virtual planetarium.
AstroViewer - Dirk Matussek's really well done planetarium applet with 1400 stars. Nice user interface. Can generate printable charts (pdf format too.)
Sky View Cafe - Another virtual planetarium with planetary orbits and ephemeris, calendar, and Jovian/Saturn moons. Easily jump to a number of celestial events.
Sky & Telescope Interactive Sky Chart - A planetarium applet from Sky and Telescope magazine. Can generate printable sky charts.
Stars and Constellations - Information and views of the constellations. Includes interactive star charts.
Fourmilab - John Walkers's collection of online software including Earth and Moon Viewer, Solar System Live and Your Sky.
GeoAstro Applet Collection - Juergen Giesen's collection of small astronomy applets.
Night Sky Observer - Lots of astronomy news.
Star Journey: The Heavens - Star Chart @ nationalgeographic.com
SEDS - Home of Nine Planets Solar System Tour, Messier Deep-Sky Catalog, and various other gems.
Heavens Above - Satellite and star observation maps.
Virtual Solar System - Virtual reality tour of the solar system from National Geographic.
Solar System Simulator - Generate pictures of solar system bodies from many different viewpoints. From NASA/JPL/Caltech.
Orbiter - A visually stunning and realistic spacecraft simulator for Windows.
