Saturnus

Saturnus is the Latin name for Saturn, the sixth planet from the Sun and the second-largest in the Solar System after Jupiter. It is a gas giant with a prominent ring system and many moons. Saturnus is a central object for the study of giant-planet atmospheres, rings, and moon–ring interactions.

Physical characteristics: Saturnus is composed mainly of hydrogen and helium, with a possible rocky core and layers of metallic and molecular hydrogen. Its mean density is about 0.687 g/cm3, so it would float in water if a large enough ocean existed. A rapid rotation gives a day of about 10.7 hours.

Orbit and rings: It orbits the Sun at roughly 1.43 billion kilometers (9.5 AU), completing a year in about 29.5 Earth years. The visible rings are made of countless ice and rock particles and are divided into several main ring groups, including the Cassini Division between the A and B rings.

Moons and notable features: Saturnus has more than 80 confirmed moons. Titan is the largest moon with a thick nitrogen atmosphere and methane lakes. Enceladus ejects water-ice plumes from its south pole, contributing material to Saturnus’s outer rings.

Exploration: Spacecraft visiting Saturnus include Pioneer 11, Voyager 1 and 2, and Cassini–Huygens (1997–2017). The Huygens probe landed on Titan in 2005, providing direct data about its surface and atmosphere.

Naming: In Latin, Saturnus refers to Saturn, the Roman god of agriculture, equated with the Greek Cronus. The name appears in classical texts and is used for the planet in many languages.