Jupiter's Galilean Moons

Using this application it is possible to compute and visualize the positions of Io, Europa, Ganymede, Callisto - also known as the Galilean Satellites of Jupiter - in real time or at any given time in the past and in the future.

Upcoming Galilean Moons Phenomena

The following table lists all the upcoming events involving Jupiter's Galilean moons in the next 7 days.

Date	Local Time	Satellite	Event
Jul 17	13:38	Io	Begin Eclipse
Jul 17	16:17	Io	End Occultation
Jul 18	01:50	Europa	Begin Shadow Transit
Jul 18	02:38	Europa	Begin Transit
Jul 18	04:32	Europa	End Shadow Transit
Jul 18	05:21	Europa	End Transit
Jul 18	10:59	Io	Begin Shadow Transit
Jul 18	11:23	Io	Begin Transit
Jul 18	13:14	Io	End Shadow Transit
Jul 18	13:38	Io	End Transit
Jul 18	13:55	Callisto	Begin Occultation
Jul 18	14:30	Callisto	End Occultation
Jul 19	03:32	Ganimede	Begin Shadow Transit
Jul 19	05:10	Ganimede	Begin Transit
Jul 19	06:30	Ganimede	End Shadow Transit
Jul 19	08:07	Io	Begin Eclipse
Jul 19	08:12	Ganimede	End Transit
Jul 19	10:47	Io	End Occultation
Jul 19	20:58	Europa	Begin Eclipse
Jul 20	00:31	Europa	End Occultation
Jul 20	05:28	Io	Begin Shadow Transit
Jul 20	05:54	Io	Begin Transit
Jul 20	07:42	Io	End Shadow Transit
Jul 20	08:08	Io	End Transit
Jul 21	02:35	Io	Begin Eclipse
Jul 21	05:17	Io	End Occultation
Jul 21	15:08	Europa	Begin Shadow Transit
Jul 21	16:02	Europa	Begin Transit
Jul 21	17:51	Europa	End Shadow Transit
Jul 21	18:46	Europa	End Transit
Jul 21	23:56	Io	Begin Shadow Transit
Jul 22	00:24	Io	Begin Transit
Jul 22	02:11	Io	End Shadow Transit
Jul 22	02:38	Io	End Transit
Jul 22	17:25	Ganimede	Begin Eclipse
Jul 22	21:04	Io	Begin Eclipse
Jul 22	22:21	Ganimede	End Occultation
Jul 22	23:48	Io	End Occultation
Jul 23	10:16	Europa	Begin Eclipse
Jul 23	13:55	Europa	End Occultation
Jul 23	18:25	Io	Begin Shadow Transit
Jul 23	18:54	Io	Begin Transit
Jul 23	20:39	Io	End Shadow Transit
Jul 23	21:09	Io	End Transit

Events are defined as follows:

• Occultation: the satellite is moving behind Jupiter from our perspective, so the satellite hides when the occultation begins and reappears when the occultation ends.
• Eclipse: the satellite is moving inside Jupiter's shadow. Sunlight is blocked by Jupiter and the satellite, no longer directly illuminated, is seen to disappear when the eclipse starts and reappear then the eclipse ends.
• Transit: the satellite is moving in front of Jupiter's disk. Depending on the conditions, the satellite can sometimes be difficult to see during a transit, appearing as slightly lighter or darker than Jupiter's clouds.
• Shadow Transit: the shadow of the satellite is moving on Jupiter's disk. The shadow typically appears as a dark circular spot clearly visible on Jupiter's clouds. This event, as seen from jupiter, is analogous to a solar eclipse.

Credits

The algorithms to compute the positions of the Galilean Moons used in this application are based on the jsaa project (Javascript Implementation of Astronomical Algorithms) which, in turn, is based on algorithms published by Jean Meeus on his Astronomical Algorithms book.