Astronomers are a little unsure of the applicability of this index, but NASA's Planetary Protection Officer is all in favor.
Moon Armor Index [Explained]
Transcript
Title: Moon armor index:
Caption: How thick the shells around various worlds would be if their moon(s) were converted into protective armor.
(Roughly equals): Total moon volume/Planet surface area
[Vertical bars showing "moon armor" thicknesses for the Earth, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto, Salacia, Haumea, Quaoar, Gonggong and Eris.
Earth and Pluto's armor are notably thick, with Eris a far runner up. Earth's is labelled "43 km thick" and the height of Mt. Everest is measured at a little under a quarter of it. Pluto's is labelled "mostly Charon".
Salacia is close but noticeably smaller than Eris, and Jupiter even closer but still noticably smaller than Salacia. Further descending in thickness is Haumea, Saturn, Neptune, Quaoar, Uranus, Gonggong, and then Mars (which has a zoom in to show its 2 inch thick armor under a rover wheel.)]