Bob Moler's Ephemeris Blog

Ephemeris for Thursday, March 12th.  The Sun will rise at 8:01.  It’ll be up for 11 hours and 43 minutes, setting at 7:44.   The Moon, 1 day before last quarter, will rise at 2:40 tomorrow morning.

Tonight will be a busy one in Jupiter’s system for those watching with telescopes.  As it gets dark Jupiter’s moon Io will be in front of Jupiter and very difficult to spot.  It’s shadow may be seen as a tiny inky black dot on the face of the planet.  Io will move off the planet at 8:55 p.m.,  This will be followed by the shadow at 9:42 p.m. The fun isn’t over because the moon Europa will be appearing to approach Jupiter as Io leaves it.  Europa will disappear behind Jupiter at 12:06 a.m.  It will stay hidden until 4:32 a.m.  Europe will clear the planet earlier, but will still be in Jupiter’s shadow until 4:32.  When a moon’s in shadow, it is said to be eclipsed.  When behind the planet it is occulted and when in front of Jupiter it is in transit.

Times are for the Traverse City/Interlochen area of Michigan.  They may be different for your location.

Addendum

Io transit end at 8:55 p.m., March 12, 2015. Note Io’s shadow will leave the face of Jupiter at 9:32 p.m. Created using Cartes du Ciel (Sky Charts).

Io passes Europa about 10:20 p.m. March 12, 2015. Created using Cartes du Ciel (Sky Charts).

Europa’s occultation begins at 12:06 a.m., March 13, 2015. Created using Cartes du Ciel (Sky Charts).

Europa emerges from eclipse by Jupiter’s shadow at 4:32 a.m., March 13, 2015. Note that Ganymede has entered the picture. It appeared to pass Io at about 3:30 a.m. Created using Cartes du Ciel (Sky Charts).