Tuesday, April 03, 2012

"The dinosaurs became extinct because they didn't have a space program"

So said Larry Niven, but it isn't true. Dinosaurs became extinct because they didn't have telescopes and grain silos.

Diverting asteroids, particular the Chicxulub size objects big enough to wipe out dinosaurs, is a hard problem. Fortunately, you get most of the benefit of diverting a killer asteroid just by identifying it in advance. Advance warning allows you to evacuate the threatened area, and people are worth more than buildings. Even a year of darkened skies is survivable if you stockpile food in advance.

Detecting the potentially dangerous asteroids is the low-hanging fruit.


SM said...

An interesting opinion. Why do you think that the worst effects of Chixiclub were over in a year, and what would happen if the impact was in a major ocean and the evacuation zone was "everyone within 10 miles of the sea, or 2 miles of a navigable river"?

Will McLean said...

All of the estimates I've read for Chixlub said a year or less for the darkened skies, which is plenty to wipe out species that can't store food and either need growing plants or eat herbivores.

With a ocean impact you'd need to evacuate a lot of people. Property damage would be huge, but not extinction, if you have spotted the rock ahead of time.

And Chixlub level events are very, very rare. One hit in 100 million years is a very rare event.

Tunguska level hits are much more common, merely multiple centuries apart, but most will hit the ocean or empty land.