The ac companying illustration gives a reproduction of one of the most, marvelous photographs of modern astron omy, Keeler's spectrum of Saturn's rings, with the spectrum of the moon above and ...

Five of Saturn's moons are so-called shepherd moons, whose mass clears out their orbit by shoving away debris in their path, creating a gap between rings. As they skim past the edges of the gaps ...

15, 2017. Cassini embarked on its "Grand Finale" in April 2017, during which it dove weekly through the 1,200-mile-wide gap between Saturn and its rings. The actual images taken by cameras ...