Mercury
Position on the route: 7/45 · level needed 35 · journey (Mk0 engine) 5.8 h
By the numbers
| Distance from Sun | 58 million km |
|---|---|
| Diameter | 4,879 km |
| Gravity | 3.7 m/s² (0.38 g) |
| Day | 59 Earth days (rotation), 176 days (solar day) |
| Year | 88 days |
| Temperature | −180 °C at night, 430 °C by day |
| Atmosphere | none (exosphere) |
The story
The smallest planet and the closest to the Sun; in a 3:2 resonance it turns three times in two of its years, so one solar day lasts two Mercury years. Sunlight is about seven times Earth’s: 430 °C by day and, with no atmosphere, −180 °C at night. The surface is cratered like the Moon; the Caloris basin is 1,550 km across.
The floors of the polar craters never see the Sun and MESSENGER (2012) found water ice there: ice on the planet nearest the Sun. The game’s ‘polar shelter’ research rests on that real fact. The core takes up 85 % of the planet; iron-rich and partly liquid, it makes a weak magnetic field.
Reaching Mercury is harder than reaching Pluto: a great deal of braking is needed not to fall into the Sun. BepiColombo (ESA/JAXA) left in 2018 and enters orbit in 2026 after nine flybys.
Missions
- Mariner 10 (1974–75): first flybys
- MESSENGER (2011–15): first orbit, polar ice
- BepiColombo (2018–): in orbit in 2026
Colony note
No life in the open; with the polar-shelter research the permanently shadowed craters are settled. Solar power is plentiful.
☠ 430 °C by day, −180 °C by night: nobody survives in the open. With the polar-shelter research the permanently shadowed polar craters are settled.
What probes bring back
- Water ice in the polar craters (MESSENGER radar brightness).
- The core is 85 % of the planet; there is a weak magnetic field.
- 430 °C to −180 °C on the surface: the widest range in the system.