There sure are a lot more impacts than one would think. Kind of scary. That “we won’t see it in our lifetime” line is absolutely ignorant, could happen any second.
That “we won’t see it in our lifetime” line is absolutely ignorant, could happen any second.
Exactly so. I knew someone (now deceased, some years ago now) who had a so-called genius level IQ (north of 150) who saw a magazine open on my desk (uh, I was reading that during my break) with an article about Chicxulub or something. He said that's impossible, those things burn up in the atmosphere. :^)
About 20 years ago (and this was before the number of known Near-Earths was anything like it is today) the odds of dying in an impact (given the number of known large impacts, which has also risen, over the lifetime of the Earth), were shown to be worse than the risk of dying in a plane crash. In part that's a tribute to how safe air travel is, of course, but *most* people don't expect to die in a plane crash, and by and large we are correct about that.
My view is that the mass extinction impacts and basically all or nearly all large impacts have been by NEOs, because those encounter the Earth (usually at great distances) on very regularly and routinely, and there are a lot of them (fewer than there used to be, due to kabooms into the Earth), and a lot of encounters for each one.
I've never had much use for the Nemesis model, wherein there's a currently undiscovered outer solar system body that disturbs the Oort Cloud every x millions of years, leading to a period of near misses and one big bombardment. That's just a uniformitarian's way of tryint to feel good about random catastrophes.