The weight of an aircraft is distributed all along the aircraft. The fuselage, along with the passengers and cargo, contribute a significant portion of the weight of an aircraft. The center of gravity of the aircraft is the average location of the weight and it is usually located inside the fuselage.
Saturn's rings were discovered in 1610 by Galileo Galilei, although he did not see enough detail to know what they were. In 2004, the Cassini spacecraft began capturing unprecedented images of Saturn's atmosphere and the complex structure of its rings and moons. It is hypothesized that the rings formed when Saturn swallowed one of its moons.
Saturn has a number of shepherd moons. They are so called because they deflect material trying to leave the ring back into place. They are responsible for the gaps in the rings. Prometheus and Pandora both orbit close to the F ring. Prometheus is known to act as a shepherd for the outer edge of the F ring and Pandora for the inner edge of the F ring. Atlas was thought to be the shepherd for the outer edge of the A ring but it is now known that the shepherds are Janus and Epimetheus.