To darken the crater center even more and represent some black soot of the recent explosion (even if that isn't overly realistic, but, hey, this is SiFi), I brushed on some black pigments.
Finally I sealed in everything with matt varnish.
When I stacked a second floor onto the rock spires to store the parched ground on top of them, there was still some room in the box. So I added some spacers onto the parched ground MDF board.
That way, the craters also still fit into that box.
