The nature of mountains that form in craters on the Moon have a clear relation to the size of the craters. The larger the crater, the more complex the nature of its mountains.
I came across this revelation on the lunar scientist William K. Hartmann’s article, a deep dive on the muti-ring impact basins on the Moon.
Origin of the rings: Our paper speculated that the rings (in large lunar craters) and their regular spacing had to do with fracturing of the crust, initiated by the impact. As pointed out by Hartmann and Wood (1971), there is an uncommon type of crater that makes a transition between “ordinary” impact craters and the basins. This is a form Wood and I named “peak-ring” craters. If you arrange craters by size, you see that small bowl-shaped craters give way to craters with central mountain peaks. Among the rare craters in the diameter range roughly 300-400 km, we found examples where the central peak widens into a ring of peaks on the flat floor of the craters. It is at somewhat larger sizes that this “peak ring” fades from prominence and multi-ring basins appear at diameter above roughly 400 km. In my opinion, as of this posting in 2011, we still lack adequate understanding of the exact mechanical processes that produce the rings.– William K. Hartmann on multi-ring basins on the Moon
And so I thought I’d make the quick graphic above for people to see a clear visualization of the progression: From craters with no mountains to multiple mountain rings! It’s rather amazing to think about how these features fall into place. It unearths something fundamental in geology.
At Moon Monday I’ve covered five of these amazing craters, check them out.
Keep looking up!