Extraterrestrial object(S) with a three-mile girth(s) ... do NOT explode, they just keep barreling on!! Only small things can heat up sufficiently in the atmosphere to do this. True, but a comet isn't solid like an asteroid, so if it hit at a shallow angle much of it could have burned away in the atmosphere and ground impacts could have been limited to much smaller fragments.
... if it hit at a shallow angle much of it could have burned away in the atmosphere...Do the geometry:
The 'atmosphere' surrounding a ~4000 radius Earth is REAL thin!
About the 'shallowest' angle you can get is and Earth grazer - a path around 200 miles long maximum thru the stratosphere and troposphere.
You'd get a 200 mile long, 3 mile wide path of STUFF.
No then; just how much 'damage' does that appear able of creating?
