Some useful links:
More will be added, and suggestions are always welcome.
On-line education/outreach resources:
- Caltech astronomy outreach
- JPL (many popular astronomy links)
- The Library of Congress Astronomy Resources on the Internet
- Sky & Telescope Online Astronomy Links
- AstronomyOnline
- Imagine the Universe from the NASA GSFC
- CDS AstroWeb
- Griffith Observatory
- ispySpace.com
- StarDate
- PBS Astronomy Programs
- Popular astronomy links from UH/IfA
- Cornell astronomy links
- APOD educational links
- Astrobiology links from SDSU
Pretty pictures:
- Astronomy Picture of the Day
- Hubble Space Telescope Gallery
- ESO Gallery
- CFHT Image Gallery
- NOAO Image Gallery
- NRAO Image Gallery
- AstroPix at IPAC
- G. Paglioli's astronomy pictures
Observatories and space missions:
- NASA public website
- European Southern Observatory
- Hubble Space Telescope
- National Optical Astronomical Observatory
- National Radio Astronomy Observatory
- Palomar
- Keck
- OVRO
- Spitzer Space Telescope
- Chandra X-ray Observatory
- Fermi Gamma-ray Space Telescope
- GAIA mission
- Planck mission
Astronomy and space news:
On-line classes and free textbooks:
- Khan Academy Cosmology and Astronomy
- Minute Physics
- Teach Astronomy, Prof. C. Impey, U. Arizona
- Introductory Astronomy, Prof. R. Nemiroff, Michigan Tech
- Astronomy Notes, Prof. N. Strobel, Bakersfield College
- "Astrophysics of Planet Formation", Prof. R. Alexander, Leicester U.
- Mike Brown's "Science of the Solar System" on Coursera
- Benjamin Crowell's "Light and Matter" series
- Motion Mountain physics textbooks