I’m watching the history channel about asteroids and how we can keep them from wiping us out. There many theories as to how we could avert disaster by defecting the path of an incoming asteroid. Everyone seems to agree that nuking one is a bad idea. I’ve heard this many times before. The explanation goes something like this - if the astroid hits earth as a whole it would be getting hit with a single bullet, it we nuke it into pieces it will be like getting hit with a shotgun blast.
This doesn’t make sense to me. This explanation seems to assume it’s the difference between a .22 long rifle (for example) and a shotgun shell full of pellets. But if instead of a shot shell from a shotgun wouldn’t an equal comparison be a shotgun slug? Or in the case of a .22 the difference between a standard 40-grain bullet and a .22 LR shot shell? I’ve shot quite a few of both and I can say with certainty I would much rather be hit with the shot shell.
Also, wouldn’t the mass be about the same? In fact, if the asteroid was in many pieces wouldn’t there be a greater chance that it would burn up before it hit the earth as there is now a much higher surface to mass ratio. It seems the smaller pieces that did hit the earth wouldn’t dig in as far as one large unit and thus not kick up as much dust to block out the sunlight.
What’s the flaw in my thinking?