关于这张图
Cassini's celestial sleuthing has paid off with this time-lapse series of images which confirmed earlier suspicions that a small moon was orbiting within the narrow Keeler gap of Saturn's rings. The movie sequence, which consists of 12 images taken over 16 minutes while Cassini gazed down upon the sunlit side of the A ring, shows a tiny moon orbiting in the center of the Keeler gap, churning up waves in the gap edges as it goes. The pattern of waves travels with the moon in its orbit. The Keeler gap is located about 250 kilometers (155 miles) inside the outer edge of the A ring, which is als…
