If it helps you sleep at night, over the billions of years earth has been in its current orbit, it’s already ‘eaten’ all the high risk asteroids.
What we’re dealing with now are very much the long-long-long tail hazards.
Which do exist.
But the earths crust was molten in it’s early life due in some large part due to persistent and high volume infalling asteroids, and that time is long gone.
>What we’re dealing with now are very much the long-long-long tail hazards.
How do you know this?
And it’s a simple bit of math.
Asteroid collisions with our planet (or any other planet) destroys the asteroid.
unless something is making ‘new events’ (creating new asteroids, which we know of little/no mechanism for), we’re currently left only with asteroids which have managed to avoid impacting us or another planet for the billions of years before now they’ve been floating around the solar system.
Over x billions of years, the 1 in 1000 events have all played out. The 1 in 1000000 events have all played out, etc, etc.
So we’re just left with the lowest odds events, aka the ones with the lowest probability/lowest risk of occurring. The long-long-long tail.
It doesn’t mean we won’t get whacked by a shoemaker/levy impact in the future, just that the odds of it occurring now are very very low compared to say several billion years ago when there were far more objects floating around that hadn’t terminated their orbits into something already.
Of course, we also have a lot more incentive now to prevent such an occurrence (as we have stuff we don’t want to have destroyed now) as compared to several billion years ago when we didn’t exist.
So worth investing into. But we’re not looking for common/predictable situations, we’re looking for very unusual occurrences and hoping for enough forewarning to make it easy to deal with the consequences.
If this was a matter of dealing with high probability events, we’d have a very different approach.