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
Uranus heritage and descend to 1–5 atmospheres. The ESA evaluated a "medium-class" mission called Uranus Pathfinder. A New Frontiers Uranus Orbiter has been evaluated and recommended in the study, "The Case for a Uranus Orbiter". Such a mission is aided by the ease with which a relatively big mass can be sent to the systemover 1500 kg with an Atlas 521 and 12-year journey. For more concepts see Proposed Uranus missions. In astrology, the planet Uranus () is the ruling planet of Aquarius. Because Uranus is cyan and Uranus is associated with electricity, the colour electric blue, which is close to