关于这张图
NASA's Cassini spacecraft looks down at the rings of Saturn from above the planet's nightside. The darkened globe of Saturn is seen here at lower right, along with the shadow it casts across the rings. The image shows that even on the planet's night side, the rings remain in sunlight, apart from the portion that lies within Saturn's shadow. The rings also reflect sunlight back onto the night side of the planet, making it appear brighter than it would otherwise appear. Saturn's small moon Prometheus (53 miles or 86 kilometers across) is faintly visible as a speck near upper left. The shadow o…
