Earth-grazing asteroids as a military resource

There is evidence of dangerous "objects" hitting the earth and causing destruction in the "historic" age.

Example:

You really are a twit. If you had bothered to read all the way through my post, you would have found exactly the same url (so it shows up twice in your post, which is a touch comical).

And the object didn't explode - it just came apart. Lots of very fast moving, very hot rocks rocks (it does seem to have a stony asteroid, which is presumably why it didn't make all the way down to the ground) would have produced a huge shock wave, so it might as well have exploded, but calling it an explosion implies that the energy emerged suddenly, rather than just coupling into the atmosphere when the air got dense enough to have a significant interaction with the fast moving rock.

That insight has been formalised as a claim that the planets' orbits are chaotic over longer time scales, in such a way that the whole Solar System possesses a Lyapunov time in the range of 2~230 million years.

The exact dynamics for Tunguska are still a bit unclear but assuming it was a typical rock ice composite material then it probably did to a very good approximation explode once the hypersonic shockwave from impacting the denser atmosphere exceeded the binding forces holding it together. Most sources describe it as an explosion at about 6 miles altitude.

Finding meteorites is a lot easier in Antarctica than on Arctic tundra.

I did read it, later, and I decided to leave my text, as my reasoning is different than yours.

I think Ovenden's conjecture is probably more likely to be true in the sense that although we can't exactly predict things we can put quite good bounds on how far out of kilter things can actually get chaos wise in the solar system (barring a close encounter with a passing star or other seriously massive object shaking things up).

His conjecture is pretty much that the big guys are locked in resonant orbital patterns that avoid each other as much as possible. It seems to hold equally well for moons of planets as well as planets of suns.

It says nothing about whether or not they could contrive to say eject Mars from the solar system entirely. What is known from composition of the planets is that they didn't all form exactly where they are now.

It is still a conjecture.

The suggestion that an orbital resonance between Jupiter and Mercury could perturb Mercury's orbit enough to get it to collide with Venus is inconsistent with Ovenden's conjecture. It's matter of conflicting computer models, so nothing to get excited about.

The currently favoured hypothesis about how Earth got it's Moon does depend on that.

The surface of rocky asteroid falling through the atmosphere will get very hot, but it doesn't spend much time in the atmosphere so the core of the asteroid won't.

The surface shell will expand and peel back - and with a rock ice composite some of the superficial water will turn into high pressure steam and expand any crevices it can get into.

You've got to think about a progressive ex-foliation. At some point the high pressure steam may get to the core of the asteroid, and if that happens before it hits the ground the core - which will still be moving very fast - has a chance to get hot as well.

Reducing this down to an explosion at a single point is an over-simplification, if handy one.

I wouldn't call what you've posted "reasoning". More like scrabbling for stuff to post that might look relevant.