09.04.25

Juno Finds Callisto’s Footprint

NASA Solar System social media features Juno’s auroral discovery. 
via @NASASolarSystem on X and Facebook

As they pass through its magnetic field, Jupiter’s largest moons make “footprints” in the planet’s spectacular auroras. Footprints from three of the moons had been observed ( first image ) but Callisto’s remained elusive — until the Juno mission found it: https://go.nasa.gov/4lXhPgc

Telescopic photo taken in ultraviolet light showing the north pole of Jupiter surrounded by glowing circular tracks of blue light
Telescopic photo of Jupiters moons leaving auroral 'footprints' , taken in ultraviolet light.

image credit : NASA and the Hubble Heritage Team (STScI/AURA) Acknowledgment: NASA/ESA, John Clarke (University of Michigan)

Diagram showing the four large moons of Jupiter Callisto Ganymede Europa and Io near the planet Jupiter with curving lines illustrating how their magnetic fields are connected to Jupiters Junos orbit is also shown with its trajectory taking it through the magnetic field and close to Jupiters north pole An inset shows a photo of circular glowing trails around the north pole each labeled with the one of the four moons that created it including Callisto
Juno capturing the marks on Jupiter of all four Galilean moons. The auroras related to each are labeled Io, Eur (for Europa), Gan (for Ganymede), and Cal (for Callisto).

credit: NASA/JPL-Caltech/SwRI/UVS team/MSSS/Gill/Jónsson/Perry/Hue/Rabia