This simulation illustrates the orbits and positions of Jupiter's four largest moons on January 24, 2015, during a rare triple-moon conjunction where the Hubble observations captured three of Jupiter's largest moons parading across the banded face of the gas-giant planet: Europa, Callisto, and Io. In this representation, Europa, Io, and their shadows are seen. Only Callisto's shadow is visible due to our line of sight. We start with a polar view of the Jovian system and tilt down to the orbital plane of the moons. The satellites move from left to right across the frame, casting shadows onto the face of Jupiter. Ganymede was too far from Jupiter in angular separation to be observed.
Publication: February 5, 2015