The shadows of Jupiterís Galilean satellites #1 Io and #3 Ganymede will simultaneously transit Jupiter during the afternoon and evening of 2012 MAR 15 in North American time zones while Jupiter is above the horizon. Io itself will be transiting at the same time.
Iíve created four preview graphics. One as viewed from above Jupiterís north pole and a second as viewed from Earth. The third is an event timetable. The fourth displays the dance of the satellites and shadows with Jupiter at 90-minute intervals. They can be seen by clicking http://www.curtrenz.com/jupiter
Photos and descriptions of the event would be welcome additions to this thread.