Cassini-Huygens’ exploration of the Saturn system: 13 years of discovery

The Cassini-Huygens mission to Saturnprovided a close-upstudy of the gas giantplanet, as well as its rings, moons, and magnetosphere. The Cassini spacecraft arrived at Saturnin 2004, dropped the Huygens probe to study the atmosphere and surface of Saturn’s planet-sized moon Titan, and orbited Saturnfor the next 13 years. In 2017, when it was running low on fuel, Cassini was intentionally vaporized in Saturn’s atmosphere to protect the ocean moons, Enceladusand Titan, where it had discovered habitats potentially suitable for life. Mission findings include Enceladus’ south polar geysers, the source of Saturn’s E ring; Titan’s methane cycle, including rain that creates hydrocarbon lakes; dynamic rings containing ice, silicates, and organics; and Saturn’s differential rotation. This Review discusses highlights of Cassini’s investigations, including the mission’s final year.