Space rocks falling down. Time for a meteorite hunt?
The biggest meteorite in a century struck Chelyabinsk, Russia, on Feb. 15, when an asteroid about 55 feet (17 meters) across, with a mass of 10,000 tons, exploded in the upper atmosphere. The explosion and fireball released about as much energy as a 500-kiloton atomic bomb — 30 times more than the bomb that devastated Hiroshima in 1945.
Shock waves through the atmosphere caused widespread destruction. Flying glass from thousands of broken windows was the major cause of an estimated 1,200 injuries.
But as the physical and emotional shock wore off, residents began collecting fragments. Soon, as happens after any substantial meteorite falls, professional meteorite hunters and go-betweens were buying fragments of space rock from locals.
Twenty five years ago, this would not have happened, but both amateur and professional interest with meteorites has exploded, says Geoff Notkin, co-host of the cable TV show Meteorite Men. “I have been in the field for almost 20 years, and when I first got interested, there were only a handful of people, other than a few academics. Now there are thousands of collectors worldwide, a couple of popular publications, our TV show, high profile auctions and a number of new books.”
Much of the surge in popularity can be credited to the Internet. “In the pre-Internet age, meteorite collecting was a small hobby, and meteoritics a comparatively small science. It was difficult to connect,” says Notkin. “There was no magazine, no forum. You might meet someone at a rock show, but there was no network of collectors and enthusiasts.”
The sale of major fossils to private collectors often sparks a chorus of scientific caterwauling, concerned that scientists will be barred from private storehouses sequestering significant samples of natural history. Do professional meteorite hunters and the market they feed harm science even as they cater to people who covet chunks of ancient space?
Certainly, the motivations of scientists and collectors overlap, says Ralph Harvey, associate professor of planetary materials at Case Western Reserve University. “You would not be a private meteorite collector or a meteorite scientist if you were not jazzed about stuff that falls from space. That’s clearly what we have in common.”
But motivations vary widely in the private world, Harvey adds. “Plenty of people cross the boundary well, are part collectors and part scientists. The big difference arises with people who focus on specimens as much from a financial as a scientific or curiosity point of view.”
Chelyabinsk, Russia, was a “fireball for the ages,” says Harvey. “My sympathies go out to the people who were hurt… but I would love to have witnessed that fireball from a safe distance. It’s awesome. Dangerous but awesome.”
The oldest text?
Meteorites formed as the solar system coalesced from the primordial cloud of dust about 4.56 billion years ago. Since then, their surfaces have gathered dust, and many have suffered a gigantic collision with another asteroid. In the last few seconds of their lives, they get a black “fusion” crust as they burn through the atmosphere.
Nonetheless, meteorites are unchanged in comparison to rocks on Earth, which have been altered by squeezing, heating and chemical reactions over the eons. And that makes these messengers from the deep solar system deeply important to science.
Some meteorites are not just time capsules from the ancient solar system: the most intriguing space rocks were blasted from the surface of the moon or Mars by asteroid impacts. “They are our only tangible samples of material from Mars,” says Carl Agee, director of the Institute of Meteoritics at the University of New Mexico.
Agee says even rarer meteorites — blasted from Mercury or Venus — could be lying on some farm field or ice sheet, awaiting discovery.
What do meteorites look like?
As meteorite hunters continue to harvest a growing roster of rocks, scientists hunger for more, says Harvey. “Meteorites are still really rare. If you looking for an answer to where it all came from, it starts with meteorites, but we have a few tens of thousands of pieces [representing] an entity as big as the solar system. The rocky inner planets have been changing for billions of years, Harvey notes, so “The only way you can get at the original conditions is in these bits and pieces that were hidden in a corner of the solar system.”
Meteorite hunting, 21st century style
Meteorite hunting has transcended the “farmer finds weird rock” phase, Harvey says. “Before 1950, virtually all of them were found by farmers in fields, maybe they were plowing and hit something, or saw it fall and rushed over to pick it up. Later, most were recovered because they hit a building, a car or a road. In the last five to six years, most are now found after being seen on a video camera or other monitoring system,” such as weather radar.
After a big fireball, hordes of meteorite hunters are likely to descend on the impact zone, and they now use technology to find elusive rocks hiding across a broad landscape, says Richard Slaughter, director of the Geology Museum at the University of Wisconsin-Madison.
Slaughter, who tried his hand at meteorite hunting after a strike in Wisconsin in 2010, says hunters “have online forums and list serves; they are very strategic.” The majority of finds on a “strewnfield map” came from meteorite enthusiasts, not scientists, Slaughter says. “They are very systematic, use all the data to find the best places to look.”
Radar records and metal detectors are standard techniques to combat the “needle in haystack” problem. Metal detectors, Notkin says, are most useful for iron meteorites (typically about 93 percent iron) and stony-iron meteorites (about 50 percent iron). Detectors will also detect the more common stony meteorites, typically containing about 20 percent iron, but with more difficulty.
The Polar solution
Laws governing the collecting of meteorites vary widely, but they are unambiguous in Antarctica, where the scouring wind leaves dark space rocks exposed on the snow. Because the Antarctic treaty forbids private ownership of rock or ice samples, the U.S. Antarctic Search for Meteorites program, now in its 35th year, delivers meteorites to NASA, which catalogs and distributes them to scientists who can make a convincing case for their need.
Harvey, who directs the Antarctic search program, says its founder William Cassidy, “knew that the meteorites would have such impact on science that we should give the samples away and not lay any claim on them. It’s as if a scientist walked through the Brazilian jungle and found a lost civilization, and said, ‘Let me call the 50 best people to investigate, and I’ll step back.’ It’s incredibly altruistic.”
At the other extreme, meteorites in the United States belong to the owner of the land they smash into. In 2012, the U.S. Bureau of Land Management issued new rules that permit “casual collection” on BLM land, but require a permit for commercial and scientific collectors.
The human element
The growing number of people who march, heads down, across the landscape after a fireball are not always easy to categorize. Some are focused on making money on what they find, but most are probably “meteorite enthusiasts, the true collectors who end up spending money on meteorites, not making it,” says Agee. However, some collectors are happy to sell when the opportunity arises, and meteorite dealers may also hunt.
We mused that the meteorite hunters could be the modern counterparts of the lone-wolf prospectors, who, with pick and mule, sought gold, silver and uranium in years past. Not so, says Slaughter. “There are handfuls of professionals, and they are very knowledgeable, and much more high-tech than the old prospectors.”
The hunters differ in another respect, says Slaughter. “I think it’s actually a much more social endeavor than the loner with his mule. You want to know who is looking where, what they are finding, how it compares to what you are finding.”
Meteorites land all over the place, Slaughter says, “so you need to know how to communicate in multiple languages, be aware of different legalities. Going up to the landowner and trying to get permission to look on the land is a surprisingly human exchange. When you are out looking with a team and you’re exhausted, dealing with that requires a human element.”
A surprising synergy
We went into this story wondering about a tension between the business of meteorites and the science of meteoritics, but we came out reassured. Are private collectors hiding meteorites from science? “I hear that rap in lots of areas: fossils, minerals and meteorites,” says Slaughter of the Wisconsin Geology Museum, “but I think actually in the meteorite world, scientists and collectors have worked out a mutually beneficial arrangement.”
The scientists who study meteorites often work at universities, and classes and students make it awkward to buy a ticket after a fireball has lit up some remote location. “Working with collectors is certainly the most cost-efficient way to get pieces,” says Slaughter, “and we don’t need very much to do the analysis, a few grams is usually a treasure trove.”
Agee, who is also professor of earth and planetary sciences at the University of New Mexico, agrees, “I have good interactions with collectors. Some of them put together really impressive collections that are on a par with museum collections, and often the collectors are keen to interact with the scientific community. A number of collectors I work with have donated to museums.”
But there are exceptions, Agee adds. “Like any business, you have people who are better citizens than others. It’s a reflection of the real world.”
“There are meteorite collectors who are every bit as zealous as those who collect art, prehistoric artifacts, or anything, really,” says Harvey. “When you have a fever for that kind of stuff, and part of the reason is financial, there are collectors out there — it’s a very small percentage — who, for lack of a better word, have bent the rules, had brushes with the law.”
The publicity surrounding meteorites can actually pull samples off the woodwork, says Notkin. The “Sterley pallasite,” for example, sat for six decades on the family mantelpiece, but when it was analyzed at the Center for Meteorite Study at Arizona State University, it was recognized as one of only 86 known pallasite meteorites.
Notkin’s business, Aerolite, bought the meteorite, donated part to Arizona State, which had done the classification, and distributed parts to six researchers worldwide. “This meteorite turn out to be completely new and extremely rare, it’s one of the most beautiful ever found,” says Notkin.
The ability to contribute to significant research collections is a major motivation for amateurs, Notkin adds. “Amateur does not mean ignorant. In this scientific field, a lot of the most important contributions have been made by amateurs. As the word suggests, they do it for love, not for a stipend.”
Still, when it comes to the large, dramatic samples that museums want to grab eyeballs, the free market can impinge on short-budgeted university museums. Slaughter, for example, recently attended the Tucson Gem and Mineral Show, seeking a piece of a Martian meteorite, but the prices approached $1,000 per gram, and the University of Wisconsin Geology Museum had to decline.
At this point, the rising interest in the rocks arriving from space, among amateurs and professionals, is reinforcing our understanding of the evolution of the solar system. “We are about where the biology of natural selection was 200 years ago,” says Harvey. “Not too many years go by without the equivalent of another platypus coming along that does not fit our understanding of how meteorites relate to each other and to their parent body.”
– David J. Tenenbaum
- Meteorite Hunting: How to Find Treasure from Space, 96 pp. Geoffrey Notkin, 2011. ↩
- Up close with metoerites ↩
- Antarctic meteorites reveal solar system history ↩
- One man’s $5 million meteorite collection ↩
- Photo: the huge, goregeous Fukang meteorite ↩
- What does it look like to search for meteorites in Antarctica? Like this! ↩
- Meteorite collector proudly poses with specimen ↩