Iapetus, satellite of Saturn, has a huge mountain range along about half its equator.
On this list of our solar system's biggest mountains, it is the only entry with uncertain origin.
..The unmeasured peaks of the nameless range are estimated nearly as high as Olympus on Mars.
Here are 4 hypotheses for the equatorial ridge's formation: wiki again
(To me, the 4th sounds right but incomplete, & the rest seem unlikely)
This Guardian article says Earth's equatorial mountains are taller than lower-latitude mountains because cold-erosion has a huge effect on mountain height & snowlines etc.
..Is this part of the reason for Iapetus' high equatorial mountain range?
...Iapetus IS mostly ice...Does/Did it have glaciers?
Is Iapetus an extreme case of cold-erosion seen on Earth?