Douglas O. Revelle
Finding Meteorites(In Memory of Meteorologist Douglas Revelle)Here’s a program from our archives.ambience: timelapse recordings of meteorites explodingWe’re listening to speeded-up recordings of meteors exploding as they enter the Earth’s atmosphere. If one of these objects reaches the planet in any substantial form, it’s called a meteorite, and it’s quite a scientific prize, if you can find one. I’m Jim Metzner, and this is the Pulse of the Planet.Revelle: If you go in a typical western United States surroundings that’s flat, the chances of recovering a meteorite are not very good. The number of meteors that make it to the ground as meteorites of ponderable size, say a half a foot across, is probably less than two or three a year.Douglas Revelle is a meteorologist with Los Alamos National Laboratory. He says that, if you do go meteorite hunting, there’s one tell-tale sign that you should look for.Revelle: The rocky material that comes through the atmosphere has very little ability to conduct heat into the interior. As a result, when the rocky meteorites come through the atmosphere, they develop a crust, and this crust looks kind of like a blackish, brownish melt on the outer surface and that very often gives away the object as being a meteorite, because ordinary rocks won’t have this crust on it.But not all meteorites have that crust on them, and they can come in all shapes and sizes, as one expedition group investigating an impact in the Rocky Mountains discovered. Revelle: They did find a rare form of meteorite on the ground. And the amount of material is the smallest ever recovered. It was two grams. And it was probably something less than the size of the tip of your finger. In Argentina, a meteorite was found named Campo de Cielo, which is iron, and it is six to seven meters across. It’s the largest one I believe I know of on the ground. They’ve thought of bringing it somewhere to study it, but it’s so big it can’t be moved.I’m Jim Metzner and this is the Pulse of the Planet.