A glistening spaceship, with seven lonely years and billions of miles behind it, glides into orbit around a ringed, softly-hued planet. A flying-saucer shaped machine descends through a hazy atmosphere and lands on the surface of an alien moon, ten times farther from the Sun than the Earth.

Fantastic though they seem, these visions are not a dream. For seven years, the Cassini spacecraft and its Huygens probe traveled invisible interplanetary roads to the place we call Saturn. Their successful entry into orbit a thousand days ago, the mythic landing of Huygens on the cold, dark equatorial plains of Titan, and Cassini's subsequent explorations of the Saturn System.