Saturnian system

The Voyager probes investigated Saturn's moons, revealing Titan's atmosphere to be mostly nitrogen, not methane as previously thought. Mimas has a huge crator that must have nearly shattered the moon, Iapetus has one hemisphere much darker than the other. An additional eight satellites were found bringing the total to seventeen.
 (NASA) United States 1980 Saturnian system

The Voyager probes investigated Saturn's moons, revealing Titan's atmosphere to be mostly nitrogen, not methane as previously thought. Mimas has a huge crator that must have nearly shattered the moon, Iapetus has one hemisphere much darker than the other. An additional eight satellites were found bringing the total to seventeen.