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A Rare Treat for Your Telescope
Mutual Occultations and Eclipses of Jupiter's Moons

Jupiter has four large moons that can be seen through nearly any telescope. First observered by Galileo in 1610, these satellites orbit at different distances in the same plane above Jupiter’s equator. Every six years, pairs of moons can align with the sun several times over several months. In some of these events, one moon's shadow falls upon another and puts it into eclipse. In others, moons can line up with Earth to hide, or occult, one behind the other from our perspective. These occultations and eclipses are called mutual events.


An eclipse occurs when the shadow of the outer moon blocks the sunlight from, or eclipses, the inner moon.
As seen from earth, the eclipsed moon swiftly fades for several minutes and then returns to full brightness.




When two of Jupiter’s moons line up with each other as seen from Earth, the outer moon blocks, or occults, the inner moon. The occultation can last for several minutes or more. With a telescope with eight-inch diameter or greater, the overlaping images of the two moons can be discerened.


Line-of-Sight Occulations and Eclipses by Jupiter's Galilean Moons, 2015.

This table includes the best of the events visible from Los Angeles between February and July, 2015. All occured when the sun was below the horizon and Jupiter was at least 10 degrees above the horizon. Only the eclipses that produce a noticeable drop in brightness (0.5 magnitude or more) are included (table derived from Ephemerides of Natural Satellites and Evaluation of observations - Natural Satellites Ephemeride Server MULTI-SAT).


Selected Mutual Eclipses and Occultations by the Galilean satellites visible from California
February-July, 2015
Date
2015
Pacific Standard Time (UTC-8h) Event Change in
brightness
(magnitude)
February 01 07:29:31 p.m. - 07:33:07 p.m. Io occults Europa. 0.5
February 01 11:53:52 p.m. - 11:59:36 p.m. Ganymede occults Europa. 0.5
February 04 12:51:16 a.m. - 12:58:18 a.m. Europa occults Io. 0.4
February 08 09:27:08 p.m. - 09:29:37 p.m. Io occults Europa. 0.4
February 09 02:34:28 a.m. - 02:40:13 a.m.   Ganymede occults Europa. 0.5
February 09 05:33:46 a.m. - 05:41:56 a.m. Callisto eclipses Europa. 0.8
February 11 02:57:00 a.m. - 03:03:47 a.m. Europa occults Io. 0.4
February 15 11:23:07 p.m. - 11:26:23 p.m. Io occults Europa . 0.3
February 17 09:48:13 p.m. - 09:57:00 p.m. Europa eclipses Callisto. 0.4
February 21 06:04:37 p.m. - 06:11:02 p.m.  Europa occults Io. 0.6
February 21 06:41:28 p.m. - 06:48:51 p.m.  Europa eclipses Io. 0.9
February 23 01:20:51 a.m. - 01:23:43 a.m.  Io occults Europa. 0.1
February 23 05:42:00 p.m. - 05:47:30 p.m.  Ganymede occults Io. 0.6
February 23 06:31:51 p.m. - 06:44:54 p.m.  Ganymede eclipses Io. 0.6
February 26 06:16:53 p.m. - 06:23:54 p.m.  Io occults Ganymede. 0.4
February 26 07:31:11 p.m. - 07:40:40 p.m.  Io eclipses Ganymede. 1.0
February 26 08:27:46 p.m. - 08:38:55 p.m.  Callisto eclipses Ganymede. 0.6
February 28 08:09:33 p.m. - 08:15:42 p.m.  Europa occults Io. 0.6
February 28 09:01:36 p.m. - 09:08:34 p.m.  Europa eclipses Io. 0.9
March 02 03:18:44 a.m. - 03:21:55 a.m.  Io occults Europa. 0.5
March 02 08:05:32 p.m. - 08:11:00 p.m.  Ganymede occults Io. 0.6
March 02 09:21 56 p.m. - 09:28:49 p.m.  Ganymede eclipses Io. 0.6
March 05 08:50:28 p.m. - 08:58:07 p.m.  Io occults Ganymede. 0.4
March 05 11:34:59 p.m. - 11:45:57 p.m.  Io eclipses Ganymede. 1.0
March 07 03:21:20 a.m. - 03:28:41 a.m.  Europa occults Callisto. 0.2
March 07 11:15:01 p.m. - 11:20:50 p.m.  Europa occults Io. 0.5
March 07 11:20:43 p.m. - 11:27:15 p.m.  Europa eclipses Io. 0.8
March 08 01:26:39 a.m. - 01:49:55 a.m.  Ganymede occults Callisto. 0.2
 
  Change to Pacific Daylight Time (UTC-7h)  
March 09 11:30:31 p.m. - 11:35:51 p.m.  Ganymede occults Io. 0.6
March 13 12:31:06 a.m. - 12:39:35 a.m.  Io occults Ganymede. 0.4
March 13 02:52:14 a.m. - 03:05:52 a.m.  Io eclipses Ganymede. 0.8
March 14 12:50:07 a.m. - 01:10:14 a.m.  Io eclipses Ganymede. 0.8
March 15 01:21:18 a.m. - 01:26:44 a.m.  Europa occults Io. 0.4
March 15 02:39:00 a.m. - 02:45:05 a.m.  Europa eclipses Io. 0.6
March 15 11:46:24 p.m. - 11:58:37 p.m.  Callisto eclipses Europa. 0.9
March 19 10:39:59 p.m. - 10:44:44 p.m.  Io eclipses Europa. 0.6
March 20 03:22:36 a.m. - 03:32:20 a.m.  Io occults Ganymede. 0.3
March 21 12:47:29 a.m. - 01:09:14 a.m. Io occults Ganymede. 0.2
March 22 03:28:36 a.m. - 03:33:37 a.m. Europa occults Io. 0.3
March 23 08:15:08 p.m. - 08:17:37 p.m. Ganymede occults Europa. 0.0
March 27 12:53:22 a.m. - 12:58:18 a.m. Io eclipses Europa. 0.6
March 30 11:12:27 p.m. - 11:13:42 p.m. Ganymede occults Europa. 0.0
April 02 02:36:12 a.m. - 03:00:22 a.m.  Callisto occults Europa. 1.0
April 08 01:05:21 a.m. - 01:11:59 a.m. Callisto occults Ganymede. 0.1
April 08 08:52:05 p.m. - 08:56:05 p.m. Europa occults Io. 0.2
April 15 11:03:40 p.m. - 11:07:21 p.m. Europa occults Io. 0.1
April 18 09:59:07 p.m. - 10:08:15 p.m. Europa eclipses Ganymede. 1.1
April 20 08:42:58 p.m. - 08:48:19 p.m. Io eclipses Europa. 0.6
April 23 01:16:25 a.m. - 01:19:53 a.m. Europa occults Io. 0.1
April 26 01:16:15 a.m. - 01:24:53 a.m. Europa eclipses Ganymede. 0.7
April 27 10:58:00 p.m. - 11:03:24 p.m.  Io eclipses Europa. 0.6
May 02 07:32:01 p.m. - 07:37:13 p.m. Io occults Ganymede. 0.2
May 05 08:13:18 p.m. - 08:18:29 p.m.  Ganymede occults Io. 0.3
May 09 10:20:48 p.m. - 10:25:55 p.m.  Io occults Ganymede. 0.2
May 12 08:07:38 p.m. - 08:16:53 p.m. Ganymede occults Callisto. 0.3
May 12 11:04:37 p.m. - 11:10:25 p.m.  Ganymede occults Io. 0.3
May 17 09:09:18 p.m. - 09:12:50 p.m.  Europa occults Io. 0.2
May 19 09:33:05 p.m. - 09:40:00 p.m.  Ganymede occults Europa. 0.4
May 24 10:26:25 p.m. - 10:30:06 p.m.  Europa occults Io. 0.3
June 14 08:57:11 p.m. - 09:00:27 p.m.  Europa occults Ganymede. 0.0
July 02 08:29:01 p.m. - 08:33:22 p.m.  Ganymede occults Io. 0.1
July 07 08:46:01 p.m. - 08:51:33 p.m. Io occults Europa. 0.2