关于这张图
NASA's Cassini gazes across the icy rings of Saturn toward the icy moon Tethys, whose night side is illuminated by Saturnshine, or sunlight reflected by the planet. Tethys was on the far side of Saturn with respect to Cassini here; an observer looking upward from the moon's surface toward Cassini would see Saturn's illuminated disk filling the sky. Tethys was brightened by a factor of two in this image to increase its visibility. A sliver of the moon's sunlit northern hemisphere is seen at top. A bright wedge of Saturn's sunlit side is seen at lower left. This view looks toward the sunlit s…
