The Planet of Doubt Jupiter and Saturn and on the surface of Uranus itself. At the time "The Planet of Doubt" takes place at the turn of the 22nd century, the limited range of the spaceships ensures that Uranus can only be reached from the American base on Titan when Saturn reaches conjunction with Uranus, an event that occurs once every forty years. The Young expedition explored the planet's south pole in 2060; now Hammond takes his ship, the "Gaea", to the north pole. Finding an ocean at the north pole, Hammond sends the "Gaea" spiraling southeast until they reach land. They find the
Rings of Uranus observed the rings in different geometries relative to the sun, producing images with back-scattered, forward-scattered and side-scattered light. Analysis of these images allowed derivation of the complete phase function, geometrical and Bond albedo of ring particles. Two rings—ε and η—were resolved in the images revealing a complicated fine structure. Analysis of Voyager's images also led to discovery of eleven inner moons of Uranus, including the two shepherd moons of the ε ring—Cordelia and Ophelia. This table summarizes the properties of the planetary ring system of Uranus. Rings of Uranus The rings of Uranus are a system of rings around the