The large black circle on this image of Jupiter is the shadow of its moon Io, captured racing across the tops of Jupiter’s stormy atmosphere by NASA’s Juno spacecraft.
The shadow is about 3,600km wide but appears much larger relative to the gas giant itself.
Io is the most volcanically active body in the Solar System, its volcanism generated by the flexing and squeezing it undergoes as a result of Jupiter’s huge gravitational pull.
This image was created through raw data captured by Juno on 11 September 2019, and was processed by Kevin M. Gill.
Image credit: Image data: NASA/JPL-Caltech/SwRI/MSSS
Image processing by Kevin M. Gill, © CC BY 3.0