Researcher Takes Aim at Meteorite Structure
Alma College Chemistry Professor Melissa Strait may not be an astronaut, but she spends a lot of time around meteorites. Her recent research sabbatical involved taking meteorites and shooting them with the Ames vertical gun at the Ames Research Center in Sunnyvale, Calif.
The gun, created to study meteorite impact structures, is one of a few in the world. With National Geographic filming the experience, Strait and her colleagues, including a research student, hung each meteorite on a very fine nylon filament from the roof of the gun. When shot, the meteorite shatters, and the pieces fly off and penetrate aluminum foil detectors.
“It takes a couple of hours to do one shot, so we can only do four or five a day. It was the first time I was able to go to the gun, though, so it was very exciting,” says Strait.
Melissa Strait with meteorite samples.
As a result of the project, Strait has spent time weighing the pieces of the shattered meteorites. Each hole on the detectors also will be measured by scanning slides into a computer.
“Our next project with this involves the fact that some of them don’t actually penetrate the detectors. Instead, you get these little dimples that are made on the surface, so we need to figure out how to do this manually,” she says.
Ordinary meteorites, which are readily available to purchase for experiments, were used in the project. When continuing her research, Strait says her hope is to use rocks that have more water in the structure. This kind of meteorite is very rare, though.
“We did the experiment on ordinary rocks to see if we could hit them reliably,” she says. “We found we couldn’t. Out of four shots, we only hit one of them. The other three missed, even when we tried a couple of times, so we’re working with the gun to figure out how we can do that better.”
Strait currently has a meteorite sitting in water at an elevated temperature in a pressure bomb in the Kapp Science Laboratory Center. The goal is to try to force the water into the crystal structure to see if she can make her own version of the valuable meteorites.
“Preliminary information from these fake rocks will tell us if what we’re looking for is what we expect, and if we get something unexpected, then it’s more justifiable to shoot these rocks. We don’t want to waste the valuable rocks,” she says.
Posted: Mon, December 14th, 2009 at 9:27AM
