We held and examined objects that had formed in outer space more than 4 billion years ago, that had clumped together back when the solar system itself was condensing out of dust and gas, and then eons later had blazed through Earth’s atmosphere.
While many of the meteorites were not impressive looking, they were fascinating to those present at the Salt Lake Astronomical Society meeting, held May 17 in the University of Utah’s Engineering/Mines Classroom Building.
The pebbles from space were collected by Barrett and Roxanne Flowers, who live in the Kearns area and are longtime devotees of astronomy and meteorites. Most of the material was purchased, originating in falls throughout the world, although the Flowers have discovered a few meteorites themselves.
[Barrett Flowers shows how a magnet is attracted to a meteorite. Photo by Cory Bauman]
“Most meteorites look like rocks until you get them under a microscope” and inspect them carefully, Flowers said. But some seem more obviously to have originated in distant parts of the solar system.
Occasionally, an example the couple displayed still retained the fusion crust that testified to its scorching passage through the atmosphere; more often, the crust had weathered off after hundreds of years on the ground. Many had been cut and polished, and were kept in baggies along with their labels.
Among the most interesting was a specimen that showed crisscrossing internal designs, where iron and nickel had interacted in peculiar patterns. It came from Nambia, South Africa, from a meteorite fall that was observed in 1835. To bring out the patterns, it was sliced, polished and treated with a 5 percent acid solution.
Holding up another, he said it came from meteorites that fell in China about 500 years ago. “Most of them aren’t these nice, black, shiny rocks,” he said.
Meteorites can fall anywhere, Flowers added. “Depending on who you talk to, there’s between 12 and 17 known meteorite falls in Utah.”
Roxanne and Barrett flowers have been searching the Utah deserts for meteorites. “What that means is spending a whole lot of time out in the desert … You’re out looking at rocks.” They don’t find many meteorites, he added. “They’re hard to find.”
[Roxanne and Barrett Flowers passed around this meteorite specimen from Morocco. Photo by Cory Bauman]
A crucial piece of their collecting equipment is called a meteorite stick. It’s a slim pole like a pointer with a powerful magnet attached to the end. Because many meteorites contain iron, they may be attracted to the magnet. However, if a rock does cling to the magnet, that doesn’t necessarily mean it fell from space.
“Ninety percent of the rocks you find that are going to stick to a magnet are going to be magnetite or hematite,” earthly minerals that include iron. However, it’s unlikely that one would find minerals from Earth that are a combination of nickel and iron, as some meteorites are.
Another way to tell if a rock is a possible meteorite is to examine it under magnification. Often meteorites will contain chondrules, “the little round-shaped minerals that form in space or in volcanic activity.” Still, to verify that an object is a meteorite may require a laboratory analysis, which can cost as much as $1,000, he said.
Magnets used on a meteorite stick are exceptionally strong, made from rare earth materials; often, these are of a brittle mineral called neodymium. Keep these magnets away from watches because the heavy magnetism can damage them, Barrett Flowers said.
“Oh, keep it away from credit cards,” Roxanne Flowers added.
Meteorite sticks aren’t expensive to make, and “we probably lose … three to four per trip,” Barrett Flowers said. The couple will drive across desert areas checking many spots in a day. Sometimes they find that a meteorite stick, believed lost, was attached to the back of their truck.
The easiest places to find meteorites are known strewn fields, he said.
In the frigid reaches of space, where temperatures can approach absolute zero, a chunk of material from the asteroid belt may be a solid lump. When it enters the atmosphere at high speed, it will grow hot from friction with air molecules and it can break apart explosively. Hundreds of fragments may blaze through the atmosphere, some burning up as meteors and others reaching the ground as meteorites.
“It makes a large oval area, and that’s called a strewn field,” Flowers said.
“I have found two in Utah and right now they’re out there (with expert geologists) being classified,” he added. In addition, he has found a couple in Arizona that were “part of known meteorite falls.”
These objects fall to Earth frequently, with most hitting the oceans where they are never seen. Flowers said every square mile may have a meteorite hit once in 100 years. “Meteorites are everywhere,” he added. The hard part is discovering and identifying them.
[Tim Holt, left, and Salt Lake Astronomical Society president Rodger Fry examine specimens during the Flowers’ talk, while other SLAS members watch or take notes on a laptop. Photo by Cory Bauman]
Flowers, who is trying to earn some money from the hobby, says he has invested more than he has made. The Flowers give information and have offered some meteorites for sale through their WEB SITE, and sometimes sell them on eBay.
But the real rewards aren’t monetary.
“They’re the oldest thing you’ll ever likely to hold that you know have never changed. ….” Flowers said. “They’re 4 billion years old. It’s not some rock that was made here on Earth.”