4 ms·
> It's all going to fall at basically the same instant. No, not for any sane definition of "at the same instant". See Shoemaker-Levy 9 as a great analog. Compl
by burnte 3y ago
> It's all going to fall at basically the same instant.
No, not for any sane definition of "at the same instant". See Shoemaker-Levy 9 as a great analog. Completely natural forces broke it up and it fell across a huge swath of Jupiter. An engineered breakup would of course be much more fine tuned to create both chunks and vectors of our choosing.
If something were to head at us, and we took it from one big chunk to multiple smaller chunks but with such a terribly small explosion that we turn it into a closely-spaced fleet of rocks, then yes, but hopefully if we go through the effort of trying to destroy/deflect, we'd use a reasonable amount of explosive.
While your energy dispersal functions in a vacuum are correct, you're completely neglecting everything else about the situation. All the energy we're putting into the system to change the vectors to start with, you're acting like we barely tap it. Look at what happened with DART and that had zero explosive, that was _purely_ ballistic. You hit a rock several months out and send pieces flying in 18,000 directions, some hit us, some don't, they hit across weeks, they hit across the world, and you get the benefit of our atmosphere. Presuming optimal angle of attack for the interloper, everything under 100 meters in diameter is vapor. More acute angles take that number up, and at really steep angles the objects skip off the atmo. Larger rocks will airburst from the entry into atmo, and lots of stuff will make landfall, but again, ALL THAT ENERGY IS DISPERSED ACROSS SPACE AND TIME. I know you said it won't, but the math, and real-world examples, say it will.
> Thus big rocks must only be deflected, not destroyed.
The problem is most things aren't just big rocks, the things that endanger us also consist of rock piles and slush balls, which you cannot deflect. So we MUST engineer for destruction as well.
And this discussion itself also ignores a hundred other variables such as orbital mechanics, how much time we get, composition, etc. To just say "It'll all hit at the same time and we can only deflect" is only correct, pardon the pun, in a vacuum. There's more to consider.