The Moon
3,475 km (2,159 mi)
Equatorial diameter
Earth's only natural satellite. Diameter: 3,475 km, a little over a quarter of Earth's.
Published
How big is that?
3,475 km is 393 times Mount Everest and 27% of Earth.
The Moon is the 16th largest of the 39 Cosmic Scale objects, and the 16th largest of the 109 objects across all three SizeItUp games.
Size comparison
To scale, smallest to largest: The Moon in orange beside the Cosmic Scale objects nearest in size, in teal.
| Object | Size | vs The Moon |
|---|---|---|
| Triton (Moon of Neptune)Neptune's largest moon, which orbits backwards. | 2,706.8 km across | 78% of the size |
| Europa (Moon of Jupiter)An icy moon with an ocean hidden under its cracked crust. | 3,121.6 km across | 90% of the size |
| The Moon | 3,475 km across | – |
| Io (Moon of Jupiter)The most volcanic world in the Solar System. | 3,643 km across | about the same |
| Valles Marineris (Mars)The great canyon system of Mars, seen from above and measured end to end. | 3,870 km long | 1.1× bigger |
In other units
| Metres | 3,475,000 |
|---|---|
| Kilometres | 3,475 |
| Feet | 11,400,000 |
| Miles | 2,159 |
How it's measured
Equatorial diameter. NASA Planetary Fact Sheet.
Planets spin, so they bulge at the equator: the equatorial diameter is a little larger than the distance from pole to pole.
Sources
- nssdc.gsfc.nasa.gov: Moon: 3,475 km.
Checked against the source on .
Could you have guessed it by eye?
The Moon is one of the objects in Cosmic Scale, a daily size comparison game: you stretch a shape to the size you think is right beside one you know.