The Moon
Position on the route: 2/45 · level needed 3 · journey (Mk0 engine) 1.2 h
By the numbers
| Distance | 384,400 km (mean) |
|---|---|
| Diameter | 3,474 km |
| Gravity | 1.62 m/s² (0.17 g) |
| Day | 29.5 Earth days |
| Temperature | −173 °C at night, 127 °C by day |
| Atmosphere | none (trace gases) |
| Journey | 3 days (Apollo) |
The story
Earth’s only natural satellite and the only other world humans have walked on. Tidally locked, it always shows the same face; the far side was never seen until Luna 3 in 1959. A lunar day is two weeks of daylight and two of night, so a solar-powered base needs batteries or the ‘peaks of eternal light’ near the poles.
There is water ice in the permanently shadowed polar craters (LCROSS 2009, Chandrayaan-1). Water means drinking, and by electrolysis oxygen and hydrogen, that is rocket fuel; that is why every current programme aims at the south pole. The dust called regolith sticks to everything, is sharp and electrostatically charged; it wore through Apollo suits.
Low gravity and no atmosphere make the Moon an ideal launch site: the same fuel sends far heavier cargo than from Earth. The game’s ‘leaving the Moon is easy’ comes from this.
Missions
- Luna 2 (1959): first human-made object
- Apollo 11 (1969): Armstrong and Aldrin
- Lunokhod 1 (1970): first remote-controlled rover
- Chang’e 4 (2019): first landing on the far side
- Chandrayaan-3 (2023): landing near the south pole
- Artemis (2020s): the return of people
Colony note
The easiest first colony: close, low gravity, ice at the poles. The hard parts: the two-week night, dust, radiation (no magnetic field).
What probes bring back
- Water ice measured in the permanently shadowed polar craters (consistent with LCROSS 2009).
- The regolith is 42 % oxygen by mass; it can be baked out.
- A 300 °C day–night swing: thermal cycling stresses equipment.
- Traces of helium-3, the isotope discussed as fusion fuel.