Re: military aircraft ...
This is what I was trying to work out. Presumably any of those could break their rated ceiling on a balistic trajectory, but you'd presumably have heard the boom over a wider area as it would have been supersonic on the approach.
The reporting makes it sound like it was a boom in a relatively localised area, which only leaves rocks, doesn't it?
With nothing non-military going above about 50,000ft I assume that radar doesn't track those heights? Or is all tracking at that height transponders anyway?