Voyager 1 revealed important details about Titan, Saturn's moon with a thick atmosphere.
Titan's atmosphere was not entirely unknown before Voyager 1 arrived: Earth-based observations and Pioneer 11 had already indicated that the moon possessed a substantial atmosphere. Voyager 1's close encounter in November 1980, however, allowed scientists to measure its composition, density, pressure, and temperature in much greater detail. Radio signals passing through the atmosphere also helped determine how it affected the spacecraft's transmission.
A dense orange-brown haze hid Titan's surface from Voyager's cameras. The measurements showed an atmosphere dominated by nitrogen, with methane and complex hydrocarbons contributing to the haze. Scientists began considering whether liquid hydrocarbons might exist on the surface, a question later explored by the Cassini-Huygens mission.
Titan is sometimes confused with Saturn's other moons, especially Enceladus, which is famous for water-ice plumes. Titan is distinctive because it has the Solar System's densest moon atmosphere and a climate cycle involving methane.