Amateur astronomer Anthony Wesley captured this February 2015 occultation of Europa by Ganymede. Europa is traveling from right to left "behind" Jupiter, and Ganymede is traveling from left to right "in front" of Jupiter. This 50-frame animated GIF was captured using an R600 (red longpass) filter at a rate of 45 fps. Each frame in the animation is the best 600/1000 frames, i.e. 22 seconds.