Diameter	3,476 km / 2,159 miles
Avg. distance from Earth	384,400 km / 238,855 miles
Time taken to turn on axis	27 days (27.321 days)
Time taken to orbit Earth	27 days
Surface gravity	0.16 (one sixth of Earth's)
Minimum surface temp.	-233 °C / -387 °F
Maximum surface temp.	123 °C / 253 °F

Accompanying Earth on its journey around the Sun is the Moon, Earth's only natural satellite. The Moon is the second brightest object in the sky after the Sun and is thought to have formed from the debris when a planet-sized object collided with Earth billions of years ago. The Moon is larger than dwarf planet Pluto and is the only object, other than Earth, to have been stepped on by human beings. Its Roman name is Luna and Greek name is Selene. Although the Moon's appearance changes due to its phases, you are only ever able to see one side of it as it always faces Earth.