10Mt (nuclear) = 900kton (mass @ 11000 m/s) = ~60m diameter ferrous rock
Impact parameters, assuming 10Mt (energy, nuclear equivalence) impacts on earth:
CRATER DEPTH: Nuclear: 60 meters Rock: 250 meters
CRATER DIAMETER: Nuclear: 2000 meters Rock: 1500 meters
IMPORTANT NOTE: According to sources, a rock must have a mass >500 tons in
order to impact at the above assumed velocity. Rocks with less than 500
tons mass are slowed by atmospheric drag to velocities less than 1000 m/s.
A one ton rock will not work.
From: Michael Lorrey:
No he showed a massive difference in ground penetration with the
advantage to rocks. He also compared what would be needed for
equivalence in damage on earth for a 10MT nuke and a rock. I am
proposing using smaller rocks, preformed as conic atmospheric
=====
Penetration isn't too relevant, as few Earth structures are underground
anyway. Terrestrial military might be in trouble, but this thread
originally started as a MAD scenario.
I don't know my drag. Would conic rocks surive? Warheads do, but do
they have special surfaces? And the shaping won't help the fact that 1
ton rocks don't have much energy; James got megaton equivalence using
very BIG rocks. Rocks big enough for Earth to use active defense
against -- to detect and break up into badly shaped fragments that burn
up in atmosphere or at least slow down.
Merry part,
-xx- Damien R. Sullivan X-) <*> http://www.ugcs.caltech.edu/~phoenix
"It was no sin, only a failure. 'And even if my troop fell thence
vanquished, yet to have attempted a lofty enterprise is still a trophy.'"
-"Forty-two years in Holy Orders, you hear all the sins in the Lexicon.
But angelism! Now there's a genuine rarey."
-- Julian May, _The Adversary_