LOOKING INSIDE METEORITES

THE INSIDE OF A METEORITE IS OFTEN MORE BEAUTIFUL and interesting than the outside. Here, the outside surfaces—visible on the larger masses of these two meteorites—are dark and dull. But the insides of these meteorites—visible on the thin slabs—can be polished to shine and reflect like mirrors.

Meteorites are not cut into thin segments just to make them more beautiful, however. Scientists often remove small pieces of meteorites to distribute this rare research material among many laboratories, ensuring wide access to the samples. In addition, nearly all scientifically important characteristics can be seen best by cutting into meteorites.

METEORITES ARE COOL

The Nama people of Namibia, in southern Africa, at one time made weapons from iron they hammered off the Gibeon meteorite. Numerous fragments of Gibeon have been identified across Namibia since a British scientist in the early 1800s recognized the iron as being of meteoritic origin.

The large mass of Gibeon on display has not been sliced; the slab was cut from a different piece of Gibeon. Like all metal, Gibeon is cool to the touch because it conducts heat away from your body. Examination of the slab reveals that Gibeon is made of metal that has crystallized in the so-called Widmanstätten pattern, found only in iron meteorites.

EXTRATERRESTRIAL STEEL

In 1907, while herding cattle in Colorado, two cowboys discovered this meteorite, a 309-kilogram (680-pound) iron mass. The American Museum of Natural History purchased the specimen, called Guffey, shortly thereafter.

No other pieces of Guffey have ever been found, yet several museums around the United States have samples of it. Over the years, researchers at this museum have removed small portions of the "main mass" of Guffey and sent them to other museums in exchange for other rare meteorite specimens. Such pieces also allow scientists to examine the inside of the sample. This slab reveals that the meteorite has a composition and structure much like that of manufactured steel.

GIGANTIC SAW

Slicing through meteorites can take many hours or even days. In 1982, researchers at the Smithsonian, using a saw that occupies an entire room, removed a 360-kilogram (800-pound) piece of their three-ton iron meteorite called Old Woman. The effort required more than 120 hours of cutting with this wire saw coated in a natural garnet abrasive. It took about 80 hours of cutting—and 47 wires—to divide the smaller segment of Old Woman even further.