Scientist: Douglas O. Revelle
The Big One – From the Sky(In Memory of Meteorologist Douglas Revelle)Here’s a program from our archives.Many scientists now believe that millions of years ago, a giant meteorite crash-landed on earth and caused atmospheric changes which eventually brought about the extinction of dinosaurs. What are the chances of something like that happening again? I’m Jim Metzner, and this is the Pulse of the Planet.Revelle: We know from the geologic record that the Earth is very heavily pocked, and in fact if we remove the oceans and look at the ocean floor, the remnant of meteorite impacts is very easy to see. We know there are major craters for example in Arizona, in Quebec, the new crater that’s been discovered in the Yucatan peninsula that’s been related to the extinction of the dinosaurs.Douglas Revelle is a meteorologist with Los Alamos National Laboratory. He tells us that major meteorite impacts are likely to continue.Revelle: The time interval between another event of the magnitude of the event that hit in the Yucatan is between ten million and a hundred million years. The current accepted age of the crater that hit the Yucatan is sixty five million years. And we know that if that event ever happened again, life as we know it on this earth will be very, very different. And we know that if we wait long enough, it’s going to happen again. Revelle: I don’t think it’s the kind of thing where people should go home and worry that tomorrow the Earth is going to end. I don’t think this is what we’re saying. Because you have to realize that these numbers are statistics. This is on the average how frequently is the earth hit. It could be that it’s hit more than that, or it could be that it’s hit less than that. The rate at which these objects fall can change as time changes.So statistically, a good sized meteorite is due for a rendezvous with planet earth in the next few million years, but you probably shouldn’t stop making your mortgage payments just yet. I’m Jim Metzner, and this is the Pulse of the Planet.