Isn't It Weird That You Can Do Synchronous Orbit On Minmus, But Not The Mun?

[Nicodo123]

I find it weird because Minmus is way smaller than the Mun, and has a smaller gravity well.

Edited April 10, 2021 by Nicodo123

[paul_c]

Mun is tidally locked but Minmus isn't, that's the main reason.

[pandaman]

It's to do with the rotational speed of the body and the extent of it's Sphere of Influence.

The more slowly it spins the higher up you need to orbit to synchronise.   If it spins slowly enough then the orbital height required is greater than the SOI, which means you can't do it.

Also, a bodies SOI is related to how close it is to it's parent body.  Mun's SOI would be bigger if  it were further away from Kerbin.