Two days ago, on the Facebook, I linked this always pleasant bit of information: we dodge extinction because a huge asteroid will sail right past us on Halloween. (And by “right past us” I mean, c. 300k miles). What gave me a slight chuckle was the article’s admission that this asteroid was just discovered, as in: “Oh crap, there it is; and it’s coming fast.” No time to rustle up some guys from an oil rig, train them in space flight, launch them into space, blah, blah, blah. Nope. This cosmic beanbag is almost here. It also gave me a chuckle because the story reminded me of something I read from Bill Bryson, who always gives me a chuckle.
After supplying a useful analogy for the sheer number of asteroids and the Earth’s interaction with them, Bryson writes:
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.”
–Bryson, A Short History of Nearly Everything (2003), 171
A few pages later, Bryson unfolds the really good news:
I asked [Ray Anderson and Brian Witzke] how much warning we would receive if a similar hunk of rock [i.e. the one that caused the Chicxulub crater] were coming towards us today. “Oh, probably none,” said Anderson breezily. “It wouldn’t be visible to the naked eye until it warmed up and that wouldn’t happen until it hit the atmosphere, which would be about one second before it hit the Earth. You’re talking about something moving many tens of times faster than the fastest bullet. Unless it had been seen by someone with a telescope, and that’s by no means a certainty, it would take us completely by surprise.”
The next three pages are fairly detailed educated guesses as to what would happen next. It ain’t pretty. Happy weekend, everybody.