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.
(currently unavailable)

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.