NASA’s Juno spacecraft saw Ganymede cast a large, dark spot on Jupiter during its 40th close pass by the planet on February 25, 2022.
JunoCam captured this image from very close to Jupiter, making Ganymede’s shadow appear especially large. The Juno spacecraft was about 44,000 miles (71,000 kilometers) above Jupiter’s cloud tops and 15 times closer to the planet than Ganymede at the time the raw image was taken.
An observer at Jupiter’s cloud tops within the oval shadow would experience a total eclipse of the Sun. Total eclipses are more common on Jupiter than on Earth for a number of reasons: Jupiter has four major moons (Ganymede, Io, Callisto, and Europa) that often pass between Jupiter and the Sun, and since Jupiter’s moons orbit in a plane close to Jupiter’s orbital plane, the moon shadows are often cast upon the planet.
Jupiter is, by far, the largest planet in the solar system. In fact, it is more than twice as massive as all the other planets combined. It is fifth in line from the Sun. Jupiter’s iconic Great Red Spot is a gigantic storm bigger than Earth that has raged for hundreds of years. Its familiar stripes and swirls are actually cold, windy clouds of ammonia and water, floating in an atmosphere of hydrogen and helium.