Fact #191
Strange but true
The Moon is 3,475 kilometres wide — about the distance from London to Cairo, or a little less than the width of the contiguous United States.
It is a quarter of Earth's diameter, which is a ludicrous ratio for a planet and its moon: nothing else in the solar system comes close except Pluto and Charon. The surface area works out at about the area of Africa plus Australia, all of it landscape, and nobody has walked more than a few kilometres of it.
Source: NASA Moon facts (opens in a new tab) · checked Sep 2026