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
Exploration of Uranus Exploration of Uranus The exploration of Uranus has, to date, been solely through telescopes and NASA's "Voyager 2" spacecraft, which made its closest approach to Uranus on January 24, 1986. "Voyager 2" discovered 10 moons, studied the planet's cold atmosphere, and examined its ring system, discovering two new rings. It also imaged Uranus' five large moons, revealing that their surfaces are covered with impact craters and canyons. A number of dedicated exploratory missions to Uranus have been proposed, but none have been approved. "Voyager 2" made its closest approach to Uranus on January 24, 1986, coming within of the planet's