It *vaporized* the islet (i.e. heated the rock to whatever the vaporization temp of silica is) or *disintegrated* it? (I.e. blew it to bits?)
I’ve implicitly defined “vaporize” in this thread as “reduce to chunks of molecular size,” such a size being the size of various vapor molecules. By that definition, a portion of an asteroid can and would be vaporized by a nuke, but not the entire asteroid.
BTW, “disintegrate” would imply “reduce to chunks of atomic size.”
From what I’ve read, most of the threateningly-large meteors with sufficiently-erratic orbits in the solar system have been cleaned up by the gravitation of larger bodies like, say, Jupiter.
Sort of. But Jupiter can still perturb the orbits of Belt asteroids enough to make them a threat to Earth, or to other worlds. Not to mention that asteroid and comet strikes on other worlds might throw up enough rocks into orbit around the Sun, too.
Much more dangerous are comets, and mass-for-mass a comet impact has a much worse effect on the celestial body it hits.
It depends on the comet. An older comet with much of its volatile base depleted would be smaller and less devastating. Problem is comets are odd-balls in every sense. I mean they have eccentric orbits, very high speeds near the Sun and we’ve no idea how many loose ones there are.
Jupiter has a huge effect on comets, too, when they pass sufficiently close to it. In this case, though, a non-thretening comet could change orbit due to a close pass by Jupiter to become a threat in its next visit to our side of the Solar System.
Bottom line we ought to be worried and vigilant.
Given NASA exists and operates a space program of sorts, it would be a good idea to task it with planetary defense against such threats. That means funding a search and identify program, plus funding missions to such asteroids and comets within reach, plus devising strategies to divert them.
I admit the mass driver schemes seem more certain to divert asteroids and comets, and to keep them away for good. But we should explore all options and keep all means ready.
A nuke in the megaton range could do it in a *flash*. The 15 Megaton IVY MIKE test vaporized an entire islet several thousand feet long. A nuclear explosion on Earth(including an airburst) is mainly a fluid dynamics problem, a nuclear explosion in space is governed by radiation/plasma physics. Keep in mind D’kian that explosion generated shock waves are compressional waves, and so they require a medium to propagate of which outer space is decidedly lacking.