关于这张图
Cassini has sighted Prometheus and Pandora, the two F-ring-shepherding moons whose unpredictable orbits both fascinate scientists and wreak havoc on the F ring. Prometheus (102 kilometers, or 63 miles across) is visible left of center in the image, inside the F ring. Pandora (84 kilometers, or 52 miles across) appears above center, outside the ring. The dark shadow cast by the planet stretches more than halfway across the A ring, the outermost main ring. The mottled pattern appearing in the dark regions of the image is 'noise' in the signal recorded by the camera system, which has subsequentl…
