Kevin M. Gill, a software engineer and data wrangler at NASA-JPL, created the fantastic video below "using still images taken by the Cassini spacecraft during it's flyby of Jupiter and while at Saturn.
"Shown is Io and Europa over Jupiter's Great Red Spot and then Titan as it passes over Saturn and it's edge-on rings," Gill wrote on Flickr.
People seemed to like the Europa/Io/Titan gifs, so as an experiment I went and made a short video of them. The Voyage of the Moons.
— Kevin M. Gill (@kevinmgill) October 22, 2018
image credit: NASA/JPL-Caltech/SSI/CICLOPS/Kevin M. Gill