Jupiter on December 23, 2011 at 7:30 pm CST
Jupiter's red spot is visible and Io and Ganymede are on the left.
Jupiter on December 22, 2011 at 8:00 pm and 9:30 pm CST
Io and Europa are on the right.
The shadows of Ganymede and Io transit Jupiter at 12:20 am CST
on March 21, 2004. Io is visible as a small reddish spot just to the
left of its shadow, which is the rightmost shadow of the two.
Callisto partially occults Io on January 17, 2003, from 4:08 am to 4:27 am.
We can only see these kind of events on those rare occasions when the earth
and Jupiter are lined up just right during their orbits around the sun.