New! I have a Javascript Jupiter's moons page -- prettier, more features, and no Java required. That said, if you still want the Java version:

The "Juplet" Java applet shows the positions of the four Galilean satellites of Jupiter, their shadows, and the great red spot.

To show the positions of the moons at a different time, edit the date in the text field then hit return to recalculate. If you see "Can't Parse Date" or the time appears to be off, or if you have any other problems and want to send a bug report, first see my bug report page.

Current GRS position: system II longitude 80. some years one can find its location at the ALPO Jupiter section.

This applet is also available as part of a Zaurus PDA package.

I have some sketches of what small telescopes will show on Jupiter and other astronomical objects.

Some other Jupiter links

• International Jupiter Watch Atmosphere Discipline
• LAS News and Observations Good listings for Jovian moon events, barges, ovals, etc.
• Transit times for Jupiter's Red Spot
• My Jupiter applet
• If you don't like my applet, here are some other ones:
  • JupRot program on the ALPO site shows several features but unfortunately doesn't label them
  • Los satelites galileanos Jordi Mas' applet. Documented in Spanish (but fairly easy to figure out even for non-Spanish speakers). Includes animation! If the main page doesn't finish loading, don't worry about it, just click on the button to get the applet.
  • Skynotes page, or you can download it
• Galilean Satellite Mutual Occultations and Eclipses in 1996-1998
• PHEMU97 Observations of Mutual Galilean Satellite Events
• Jupiter satellite events and GRS times for the rest of 1997 from Project Pluto