Tonight’s Sky, Explore Astronomy, Hubble Site, hubblesite.org.
What’s Up, Jet Propulsion Laboratory, jpl.nasa.gov.
Heavens Above, heavens-above.com.
Current Lunar Phase, aa.usno.navy.mil.
Current Sunspot Activity, sohowww.nascom.nasa.gov
Planet Summary, heavens-above.com.
International Space Station Visible Passes, heavens-above.com.
Current Aurora Forecast, www.swpc.noaa.gov
The Evening Sky Map, skymaps.com.
Astronomy Picture of the Day, apod.nasa.gov.
Jupiter’s Moons, skyandtelescope.com.
Saturn’s Moons, skyandtelescope.com.
Stellarium, stellarium.org.
Google Sky, google.com.
Sky and Telescope, skyandtelescope.com.
Astronomy Magazine, astronomy.com.
Space.com, space.com.
EarthSky, earthsky.org.
StarDate, stardate.org.
One-Minute Astronomer, oneminuteastronomer.com.
Night Sky Info, nightskyinfo.com.
Go Astronomy, go-astronomy.com.
Astronomy Calendar of Celestial Events, seasky.org.
United States Naval Observatory Data Services, usno.navy.mil.