# Moon

*In the Solar System*

The Earth's only natural satellite and the fifth largest in the Solar System: a quarter of the Earth's width, an eightieth of its mass, with no atmosphere to speak of and a surface that swings between about 120 °C in sunlight and −170 °C at night. It is locked to the Earth by tides, so the same face is always turned this way, and it is drifting away at about 3.8 cm a year - measured by bouncing lasers off the reflectors Apollo and Lunokhod left behind.

| | |
| --- | --- |
| Radius | 1,737 km |
| Around the equator | 10,916 km |
| Mass | 7.35 x 10^22 kg |
| Compared with the Earth | 0.012 × |
| Turns once in | 27.3 d |
| From the Sun | 150,685,251 km (-112,139 km/d) |
| From the Earth | 368,607 km (-351 km/d) |
| A signal takes | 1 s |

Distances and speed are computed from JPL Horizons trajectories and are true of 2026-09-05, changing at the rate given beside each. The interpolation itself is good to a few kilometres; what ages these figures is the date, not the arithmetic.

## Elsewhere

- On the live map: https://www.orbitalmap.space/?world=solar-system&focus=moon
- This object as a page: https://www.orbitalmap.space/o/moon/
- Every object: https://www.orbitalmap.space/o/
- What this site is and what it reads: https://www.orbitalmap.space/llms.txt