There is a wealth of interesting Jupiter satellite phenomena this month.

On January 4th, you can see the 6th-magnitude star HIP20417 pass within 1 arc-minute of Jupiter; this is closer than 3 of the 4 Galilean moons, and the star appears as an extra "satellite" of the planet. (Europa appears closer, and in fact will be transiting the planet's disk during Jupiter's closest approach to the star at around 4 AM EST.)

You can see Europa make another transit on the 14th, when it crosses across Jupiter's disk between 5:37 PM and 8:14 PM EST; its shadow crosses between 7:42 PM and 10:10 PM.

On the 24th, Io transits from 6:05 PM until 8:19 PM EST and its shadow from 7:12 PM until 9:25 PM. Before the transit of Io's shadow ends, Ganymede begins a transit that lasts from 9:07 PM until 11:25 PM, and its shadow transits from 1:37 AM until 5:55 AM. During its transit, Io keeps pace with the Great Red Spot on the planet's disk.

Jupiter on January 24th, 2013, at 8:20 PM EST. Io has finished its transit of Jupiter, but the transit of its shadow is still underway. Meanwhile, Ganymede is beginning its own transit of the planet. Callisto passes far above the planet and currently is not undergoing transits. The Great Red Spot is visible near Io.