Rods from God?
Not quite ordinary firepower, but it would be interesting to know how deep a hypersonic tungsten telephone pole could penetrate granite. Whether any self sharpening characteristics might help penetration would also be interesting.
Accuracy is likely something of a barrier to successful demolition.
But those were placed in holes drilled into the rock. I think we’ve established that explosives with much more effectively that way than just splattered onto a rock.
Seeing what the BLU-109 in @smithsb’s upthread video is capable of, it seems like a tungsten telephone pole coming in from orbit could probably cleave off a large portion of whichever presidential noggin it impacted.
Assuming that being a natural rock formation that there are weak points/veins that lead to large fractures, are we allowed to pinpoint the artillery to specific points after studying the rock?
Set loose a classroom of third-graders and tell them not to break anything. That’ll do it.
A 10 cm diameter, 6 meter long tungsten rod dropped from a ~200 km orbital speed would have kinetic energy of 27.7 GJ (not including any aerodynamic losses), or about the 6.6 t TNTeq. The stresses generated at impact will certainly exercise any fissures in nearby rock and will likely melt and possibly vaporize the tungsten at the tip (no mean feat at a melting temperature of 3,695 K and vaporization point of 6,203 K), blasting free and likely liquifying rock at the impact point and ‘self-sharpening’ (i.e. vaporizing or shearing the outer layers of the penetrator while the core drives deeper) similar to how a sabot penetrates tank armor. The ‘Rods from God’ concept was intended to provided guided strike capability to deeply embedded structures like missile silos and control centers so at least conceptually it would be capable of ‘precision’ targeting of a large monument such as Mount Rushmore. I don’t know that a single strike would destroy the entire edifice but it would almost certainly do extensive damage if it hit a few meter inward from the face, and repeated strikes would likely shear the entire existing face, also showering people at the visitor center and the parking lot with lethal debris.
Stranger
Brings to mind the “Saddamizer”. A large solid steel cone behind a large bomb, designed to penetrate a 50-foot-deep concrete-covered bunker in Baghdad. allegedly it did the job.
i would imagine dropping thes from above on the top of their head and hopping to spall off the face(s).
Dagnabbit . . . ninja’d so many times in just six days, but I guess that’s what I get for only having five minutes here and there to surf the SDMB on any given week.
Define “rubble”. Do you want to vaporize the site, or reduce the faces to a level of scree similar to whats already there post-construction?
Nobody’s brought up the Hall of Records Tunnel yet, but that’d be my first go-to instead of drilling holes for slower-moving mining explosives. Pack it with enough high-power, high-brisant explosives, and you’ll shake something loose.
. . . unless you’ve got a GBU-57 up your sleeve.
Tripler
I have more tricks up mine, but have to run . . . ‘Honey-do’ list stuff.
How about an Illudium Q-36 explosive space modulator?
Sounds a trifle over-specified for the task.
It would definitely do the job. I never said there wouldn’t be collateral damage. Would solve global warming, too.
Those formations beside Lincoln’s head seen ideally shaped for monkey heads, if someone is seeking to add to Mt. Rushmore… or Mutant Ninja Turtles.