I wonder if just the atmosphere would've caused it to explode already. At those speeds it'd go through the atmosphere within a second though.
A column of air weighs ~1kg/cm^2 (handy!), and the example has a 15km span of "Dense Rock" which I've seen mean "Dense Rock Equivalent" in the Volcanic Explosivity Index, where it has a density of 2,500 kg/m^3. Assuming that, a column of the asteroid is
2500kg/cm^2/(100cm/m * 100cm/m) = .25kg/m * 15km = 3,750kg
The kinetic energy per column of the impactor is 1/2mv^2, or 0.5 * 3750 * 80000m/s^2, or
1875 * 6.4e9m^2/s^2 = 1.2e13 Joules
Which is about 20 gallons of gasoline equivalent. As you say, that's absorbed in ~1s (space is 100km up, so 80km/s is just about right). If so that warms up and starts melting the surface of the asteroid, but not much more I guess.
The whole impact is like 40000 gallons of gasoline per cm^2 of surface, or I think like 2kt TNT.
So then, not sure what the kinetics/kinematics is there. How much is released by the atmosphere impact vs then the surface stopping the asteroid.
https://chat.openai.com/share/25e4cef6-321a-43f7-8d13-40d1fd...
Summary: my initial math checks out for the total KE of the asteroid, and then we used that to look at the surface heating by the compressed atmosphere and then the Fourier heat analysis of conduction into the asteroid surface
Answer: Tho the atmosphere would be heated to 100k degrees and that's 1000x more than needed for vaporization of e.g. granite, the duration of ~1s means that only a few millimeters of surface would be vaporized by the time of impact.
I just did a compacted single-shot request in a new session and got the same answer!
It basically elided the simplifying analysis, went directly for the heat diffusion equation and based its conclusion on that. Impressive.
https://chat.openai.com/share/0c857ebd-779a-4f40-93a9-c35cd2...
Sure, milliseconds before impact the atmosphere might be super-compressed (and super-heated). Perhaps even exert considerable force. But compared with kinetic energy of that size impactor, at such speed: negligable.
Small objects 'feel' the atmosphere much stronger. Surface area vs. volume.
It's strange that in managed to get only 2x of its diameter into the crust. I though it could just get though into magma. That would make the biggest volcano ever.
Would it do more damage to the surface than a rocky asteriod of comparable mass, though? If it burrows deeper, it means it transfers more of its energy to the mantle and core of the Earth, and less to the crust. It will be like a full metal jacket bullet that goes straight through the target and transfers most of its energy to the wall on the other side, versus a regular bullet that tumbles and expands as soon as it hits the target.
Neat sci-fi.