The Earth's Continental Crust is Totally Weird

I've said this before in this space, but the Earth is weird. Consider this: These plots show the distribution of surface elevations on a bunch of large and small bodies in our solar system. Something should jump out pretty quickly: All have a single peak for elevation except for Earth and Mars. That's weird! Why would any planet have two different peaks for the distribution of elevation? For Earth, the explanation is relatively straight forward: we have two types of crust. Oceanic crust that und