Farmland is one of the best places to find meteorites
From the tractor seat, Bruce Lilienthal hunts for a crop he never plants but always harvests.
Ranging from tiny hunks to an occasional kitchen table-sized beast, rocks break the surface of his land every spring, pushed upward by repeated frosts. On an early May day in 2011, with corn already up, Bruce spotted a large rock jutting halfway out of his heavy black dirt. He got down and dug out a 16"-long, 10"-wide and 2"-thick specimen weighing an unseemly 33 lb. Unknown to Bruce, he’d harvested the single most unique item in his farm’s history—a meteorite.
Meteorites range in value from cents per gram to thousands of dollars per gram, and farmland is a sure bet to hold untold numbers. Between 5,000 to 17,000 meteorites land on the Earth each year, and 75% are swallowed by the ocean. The rest? Fair to say, farmland is home to tens of thousands of meteorites.
Bruce normally uses large farm rocks for erosion control on a nearby creek, but the 33-pounder was too odd for rip-rap. It had a rusty tint, was ridiculously heavy—and it clanged.
“I’ve picked untold numbers of rocks from my land, but never one that looked like a burnt pizza,” he says. Bruce dropped it on the edge of his driveway, in a pile of other unusual rocks destined for his wife Nelva’s flower garden, and forgot about it. Nelva didn’t.
“It sat there for a couple of years and people would see it and comment. I made calls and sent pictures, hoping it just might be a meteorite,” she says.
In spring 2013, the Lilienthals sought out Calvin Alexander, curator of meteorites at the Department of Earth Sciences, University of Minnesota. He’s been offered at least one hopeful specimen a week throughout his 40-year career and repeatedly disappointed rock hunters.
“I’ve seen thousands of samples and all but three have been meteor-wrongs,” he chuckles. “Yet, the Lilienthals walked in and I was immediately 99.9% sure they had a meteorite.”
At 92% iron, 7% nickel, and a 1% mix of sulfur, carbon and other elements, the Lilienthal’s meteorite was part of an asteroid, formed 4.5 billion years ago at the dawn of the solar system. Essentially, a meteorite is a leftover from the same material comprising the sun and the planets. It was pulled in by Earth’s gravity and crashed on the Lilienthal’s land at between 20,000 to 50,000 mph, Alexander estimates.
“It was probably on their farm for hundreds or thousands of years before rising to the surface,” he says.
The Lilienthals sold their specimen to the University of Minnesota, but they still keep their eyes open, hoping for another fragment. Meteorite values often translate to publicity, a proposition shunned by many producers who remain quiet about finds.
“Today, we still look from the cab and wonder. We were just doing what all farmers do in our area and got lucky,” Bruce says.
“The probability for another farmer to find a meteorite is as high as the Lilienthal find,” Alexander adds. “Without question, a lot more meteorites are waiting to be found on farmland.”