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
Climate of Uranus caused it to expel most of its primordial heat, leaving it with a depleted core temperature. Another hypothesis is that some form of barrier exists in Uranus's upper layers which prevents the core's heat from reaching the surface. For example, convection may take place in a set of compositionally different layers, which may inhibit the upward heat transport. Sources Climate of Uranus The climate of Uranus is heavily influenced by both its lack of internal heat, which limits atmospheric activity, and by its extreme axial tilt, which induces intense seasonal variation. Uranus' atmosphere is remarkably bland in comparison to the