The Cassini spacecraft looked down at the rings of Saturn from above the planet’s nightside to take this picture. The darkened globe of Saturn is on the lower right, along with the shadow it casts across the rings. Even on the planet’s night side, part of the rings remain in sunlight, and they reflect sunlight back onto the night side of the planet, making it appear brighter than it would otherwise appear.
Saturn’s small moon Prometheus ( 86 km across) is faintly visible as a speck near upper left. Earlier in the planet’s year, Saturn’s shadow was once long enough to stretch to the orbit of Prometheus, but as northern summer solstice approaches, the shadow no longer reaches that far. Prometheus won’t be in the planet’s shadow until the progression of the seasons again causes the shadow to lengthen.
Image Credit: NASA