In the Solar System
Moon
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
- Turns once in
- 27.3 d
Everything the map shows is worked out in your browser from published orbital data - nothing on it is a stored picture of where things were.