- "The Mun's discovery is widely regarded as one of the more important breakthroughs of Kerbal evolution. Granted it didn’t happen all that long ago, but its still fair to say that Kerbals are wiser and more evolved now than they were back then."
- ―Kerbal Astronomical Society
Mun, also known as the Mun and sometimes written as Mün, is a relatively large moon orbiting Kerbin. It can be thought of as an analogue to Earth's own moon, which frequently is simply called “the Moon.”
It is gray in appearance with craters of various sizes and mountains exceeding 5029 m in height. The gravitational pull on the surface is 1.63 m/s², approximately 1/6 and 8.18 m/s² lower than that of Kerbin and about the surface gravity of Earth's Moon (1.624 m/s²).
The Mun's terrain is rough, grey, and scarred by craters. Its low-lying areas tend to be darker in colour. The Mun also features canyons which can be hundreds of meters deep and a few kilometers long.
The Mun's highest points reach a maximum altitude of more than 7061 m near the south pole, allowing crashes with terrain while being in a seemingly stable orbit. Its lowest point, below -247 m, is on the northern hemisphere.
The Mun's orbit keeps it directly above Kerbin's equator. Because the Mun is tidally locked to Kerbin with a perfectly circular, non-inclined orbit, exactly 50% of the Mun's surface (excluding areas on the edge obscured by the Mun's mountains) is ever visible from Kerbin. Due to the Mun's non-inclined orbit, Kerbolar eclipses occur every time the Mun goes between the Sun and Kerbin.