Uranus
Position on the route: 23/45 · level needed 170 · journey (Mk0 engine) 38.1 h
By the numbers
| Distance from Sun | 2.9 billion km (19.2 AU) |
|---|---|
| Diameter | 50,724 km |
| Gravity | 8.7 m/s² (cloud tops) |
| Day | 17 h 14 min |
| Year | 84 years |
| Temperature | −224 °C (the coldest planet) |
| Axial tilt | 98° |
| Moons | 28 known |
The story
The planet on its side: with a 98° tilt each pole faces the Sun for 42 years and then sits in darkness for 42. An ice giant; under the hydrogen–helium envelope lies an ocean of ‘hot ice’ of water, ammonia and methane. Methane absorbs red light, hence the pale blue-green.
There is no surface to land on; pressure and temperature rise with depth, and what we call the surface is the cloud tops. In the game a station can therefore only be built with the orbital-habitat research. Uranus’s magnetic field is tilted 59° from its spin axis and offset from the centre, a puzzle still not fully understood.
Voyager 2 (1986) is the only visitor; it found 13 rings and 10 new moons. The moons carry names from Shakespeare and Pope (Titania, Oberon, Miranda). In 2022 the US National Academies named a Uranus orbiter the priority mission of the decade.
Missions
- Voyager 2 (1986): the only flyby
- Uranus Orbiter and Probe: proposed for the 2030s
Colony note
No surface; the orbital-habitat research is needed. Power is the problem: sunlight is 1/370 of Earth’s.
☠ A gas giant: there is no surface to land on. With the orbital-habitat research a station is built in orbit.
What probes bring back
- The magnetic field is tilted 59° from the spin axis and offset from the centre.
- Cloud tops at −224 °C: the coldest planet.
- 13 rings and 28 moons counted.