eRe4s3r wrote on Mar 19, 2018, 13:55:
Where does this notion come from that you can't nuke asteroids? The radiation (xrays!) and light emissions from a nearby (not impact) blast would push an asteroid off-course far more than a kinetic impactor ever could.
you can nuke'em all you want, but it's finding the ones you want to nuke that's the issue (and that's not taking into account what direction they will go spinning into the ether and colliding with other nastier rocks)
snippet from Bill Bryson's "
A Short History of Nearly Everything"
Identifying an asteroid doesn’t make it safe.
Even if every asteroid in the solar system had a name and known orbit, no one could say what perturbations might send any of them hurtling towards us. We can’t forecast rock disturbances on our own surface. Any asteroid out there that has our name on it is very likely to have no other.
Think of the Earth’s orbit as a kind of motorway on which we are the only vehicle, but which is crossed regularly by pedestrians who don’t know enough to look before stepping off the verge. At least 90 per cent of these pedestrians are quite unknown to us. We don’t know where they live, what sort of hours they keep, how often they come our way. All we know is that at some point, at uncertain intervals, they trundle across the road down which we are cruising at over 100,000 kilometres an hour. As Steven Ostro of the Jet Propulsion Laboratory has put it, “
Suppose that there was a button you could push and you
could light up all the Earth-crossing asteroids larger than about ten metres, there would be over a hundred million of these objects in the sky.” In short, you would see not a couple of thousand distant twinkling stars, but millions upon millions upon millions of nearer, randomly moving objects—“all of which are capable of colliding with the Earth and all of which are moving on
slightly different courses through the sky at different rates. It would be deeply unnerving.” Well, be unnerved, because it is there. We just can’t see it.
Altogether it is thought—though it is really only a guess, based on
extrapolating from cratering rates on the Moon—that some two thousand
asteroids big enough to imperil civilized existence regularly cross our orbit.
But even a small asteroid—the size of a house, say—could destroy a city. The number of these relative tiddlers in Earth-crossing orbits is almost certainly in the hundreds of thousands and possibly in the millions, and they are nearly impossible to track.
The first one wasn’t spotted until 1991, and that was after it had already gone by. Named 1991 BA, it was noticed as it sailed past us at a distance of 170,000 kilometres—in cosmic terms the equivalent of a bullet passing through one’s sleeve without touching the arm. Two years later, another, somewhat larger asteroid missed us by just 145,000 kilometres—the closest pass yet recorded. It, too, was not seen until it had passed and would have arrived without warning. According to Timothy Ferris, writing in the New Yorker, such near misses probably happen two or three times a week and go unnoticed.
An object a hundred metres across couldn’t be picked up by any Earth-based telescope until it was within just a few days of us, and that is only if a telescope happened to be trained on it, which is unlikely because even now the number of people searching for such objects is modest. The arresting analogy that is always made is that the number of people in the world who are actively searching for asteroids is fewer than the staff of a typical McDonald’s restaurant. (It is actually somewhat higher now. But not much.)
end
snippet
"I expect death to be nothingness and by removing from me all possible fears of death, I am thankful to atheism." Isaac Asimov