Jupiter, Io’s shadow, Io, Europa, Ganymede

On the night of February the 12th-13th, 2015 I recorded how Jupiter and its moons have danced. I used a 150/750 Newtonian mounted on a motorized EQ3 mount, a 2x barlow, extension tubes (about 15cm) and a 640×480 @8bit webcam (Scopium) (see my setup here).

From 19:28 to 0:36 (local time, UTC+2) I recorded 234 GiB of raw video (93 files between 1 and 3 GiB) trying to emphasize the key events rather than just record at a given speed – making the animation speed up and slow down accordingly.

Individual frames of the animation are each a result of stacking the best 185 frames of each video (Registax 6). These results have been aligned with PIPP then touched up with IrfanView’s batch processor. Since three setups have been used, the resulting frames had to be resized and rotated to match up in the final output.

Due to a minor hardware failure and/or equipment change (adding an extension tube) recording had to be stopped – out of the 84, 6 frames have been generated using recorded data to fill in these gaps (by derotating Jupiter’s disk and manually adding the moons). I also dropped frames so frame numbering is not incremental.

These are the events I captured

• Io transiting in front of Jupiter, casting a shadow on the disk (solar eclipse on Jupiter) (frames no. 1-10)
• Io (partially?) occults Europa (frames no. 18, 19)
• Europa gets behind Jupiter (frame no. 32)
• Io (partially?) occults Ganymede (around frame no. 64)
• Part of Ganymede gets into Io’s shadow (solar eclipse on Ganymede) (frame no. 73)
• Europa comes out from behind Jupiter but it is still invisible. Then comes out of Jupiter’s shadow (end of a solar eclipse on Europa)

Io’s shadow on Ganymede (rendered in 2016 from the original data)

A solar eclipse on Ganymede