Jupiter's Moons

by Akkana Peck

This Java applet shows the positions of the four Galilean satellites of Jupiter: Io, Europa, Ganymede, and Callisto.

To show the positions of the moons at a different times, days, or years, edit the date text field then hit return to recalculate.

Bug warning! If your system is currently using daylight savings time, there is a bug in the Java engine of some navigators, including both MS Internet Explorer 3.0 and Netscape versions 3.01 and earlier, which incorrectly adds 1 to the date typed in, even if you specify daylight savings time (e.g. "PDT") or UTC in the date string. Netscape 4.0 does NOT have this bug.

To work around this bug, if your system is currently using daylight saving time, you will have to specify a time one hour earlier than the time for which you really want to see the moons.

Copyright 1996 by Akkana Peck (http://www.best.com/~akkana). Most of the equations come from Jean Meeus' Astronomical Algorithms, from Willmann-Bell.