Jupiter and Earth are converging for a (relatively) close encounter in early February when the giant planet is at opposition–that is, directly opposite the sun in the midnight sky. This sets the stage for an extraordinary sequence of events. For the next couple of months, backyard sky watchers can see the moons of Jupiter executing a complex series of mutual eclipses and transits.
The moons of Jupiter will be passing in front of one another and in front of Jupiter with fair frequency through March 2015 and beyond. This is happening because Jupiter’s opposition on Feb. 6th coincides almost perfectly with its equinox on Feb. 5th (when the Sun crosses Jupiter’s equatorial plane). It is an edge-on apparition of the giant planet that lends itself to eclipses, occultations and transits.
The next big event is right around the corner. On Jan. 24, 2015, beginning at approximately 06:26 UT (1:26 AM EST), the three moons Io, Callisto and Europa will simultaneously cast their inky shadows on Jupiter’s cloudtops. This is called a “triple shadow transit,” and it is rare. The timing favors observers in North America where the planet will be shining high in the sky in the constellation Leo.