Jupiter's moons Ganymede and Io met in the sky on October 20, 2026, and the encounter was captured in a video featured as NASA's Astronomy Picture of the Day on October 28, 2026. In the footage, Ganymede briefly blocks Io from view. When one astronomical object passes in front of another and completely or partially blocks it, the event is called a mutual occultation.

Such occultations among Jupiter's Galilean moons are rare to observe because they depend on Earth's edge-on view of the moons' orbits, which occurs roughly once every six years when Jupiter reaches its equinox and appears less tilted. According to the accompanying explanation, Jupiter currently has 115 known moons, while Saturn has the most, at 293.

The explanation also notes that Ganymede casts its shadow on the right side of Jupiter, meaning any fictional Jovian species inside that shadow would experience a solar eclipse. The image is credited to Michael Wong.