Last month, as the Taurids meteor shower was unfolding, the Bay Area was beneath a dome of heavy clouds that obscured the stars above. So I sat on my couch, flipping through a seemingly infinite universe of movies on my Apple TV, until I came upon Werner Herzog’s new documentary, Fireball: Visitors From Darker Worlds. In it, the inimitable filmmaker explores the strange world of meteors and the unexpected ways these celestial objects have blazed through our imaginations, influencing history, culture, religion, and politics.  

The film is full of the wonderfully strange quips and idiosyncratic cinematography that we have come to expect from Herzog. But there was one exchange with a historian of science named Simon Schaffer that I found particularly fascinating. Schaffer recounted the story of a famous meteorite strike in 1492 in a field near the walled city of Ensisheim on the border of Germany and France. Today, Ensisheim is a sleepy, bucolic place. But at the time of the impact, it was an important hub of military power for the Habsburg Dynasty and the Holy Roman Empire. 

To those living under the rule of the Habsburgs, Schaffer explained, the meteorite strike was viewed as a divine occurrence. “This was, as it were, an email sent from God to the subjects of Maximilian, to tell them his rule was legitimate, that he would defeat his enemies and that they should obey his command.” (Or, as Herzog surmised in his trademark, acerbic narration, it was here in Alsace where “the Habsburg Empire earned legitimacy through a falling piece of rock.”) Moments later, Schaffer dropped the pretense of academic neutrality: “I think that is a very powerful and eloquent idea, the idea that meteorites have meaning,” he said. “The task of humanity is to interpret what that meaning is.” 

But how?

An understanding of where these space rocks come from and what they are made of is, I think, a good place to start. A meteoroid is a fragment of rock floating in space, a remnant of a planet, comet, or other celestial body. These fragments vary in size from hundreds, even thousands, of feet across to no larger than a grain of sand (an asteroid is larger than a meteoroid, and some meteoroids are bits of asteroids that have collided with each other and broken apart). Meteoroids become meteors when they burn up on entering Earth’s atmosphere. A meteor, in essence, is the flash of light, the “shooting star” that we see on clear nights (and don’t see on cloudy ones, or during the day, though they are still occurring). Meteorites are the pieces that survive the trip and reach the ground. They are things you can touch—from the meteorite in your local museum burnished over the years by the touch of thousands of hands to the massive Chicxulub meteor that struck the Yucatán Peninsula roughly 66 million years ago, touching off the Cretaceous-Paleogene extinction, which led to the demise of three-quarters of plant and animal species on Earth. For the dinosaurs, the Chicxulub meteor had but one meaning: The End.  

Meteors and meteorites have inspired human beings throughout history. The al-Ḥajaru al-Aswad, or Black Stone, embedded in the central shrine of the Ka’aba in the holy city of Mecca, is, by all accounts, a meteorite said to have been anointed by Muhammad himself. The Hawaiian language contains no fewer than five different words for meteor—akualele, “flying God,” and hokulele, “flying star,” among them—hinting not only at the importance of these objects in their mythology but also the almost unimaginable darkness of the islands’ ancient skies.  

We in the West, enamored as we are of categorization, have placed these celestial objects into several classifications. There are metal-rich iron and iron-nickel meteorites that come from the metallic cores of planets destroyed eons ago. Chondrites are ancient chunks of rock, 4.5 billion years old, formed in the very earliest days of our solar system. The most beautiful space rocks are of a class called pallasites. On the outside these stones appear charred and warped, but when sliced into thin sections, pallasites often reveal a dazzling interlacing of metal and bright crystals. The most stunning specimens can take on the appearance of kaleidoscopic swirls or stained-glass windows. 

One of the most fascinating space rocks of recent times was discovered by researchers from the University of Hawaii in 2017. Dubbed Oumuamua (a Hawaiian word meaning “scout”), the cigar-shaped object was about a quarter of a mile long and careened through our solar system at 196,000 miles per hour. Because of the object's unusual shape and behavior, some scientists refused to rule out the possibility that it could be of alien origin. After many months of inquiry, researchers eventually determined that Oumuamua had originated beyond our solar system—the first object of its kind detected by human instruments—and was almost certainly completely natural. Oumuamua was most likely composed of rock and metals, its slightly reddish hue the result of hundreds of millions of years’ worth of exposure to cosmic rays.

Because meteorites come from parts of space and time that we can scarcely imagine, we tend to believe that they are rare, but this is not really the case. We are bathed in a constant rain of space dust. NASA estimates that roughly 100 tons of cosmic debris—most of it comprising microscopic particles and dust—wafts down onto Earth’s surface every day. 

At the other end of the scale, asteroids large enough to threaten Earth come around once every 2 million years or so (while movies about them, such as Deep Impact and Armageddon, seem to come around more frequently). Finding these objects falls to NASA’s Near-Earth Object Observations Program (the same group that discovered Oumuamua). With a congressionally mandated mission of planetary defense, this program engages scientists in using massive telescopes and cameras to scour the sky in search of meteoroids that are more than 140 meters wide. The goal is to identify 90 percent of these objects. They have a ways to go. “While no asteroid larger than 140 meters in size has a significant chance to hit Earth for the next 100 years,” reads a NASA press release, “less than half of the estimated 25,000 NEOs that are 140 meters and larger in size have been found to date.” (Which sounds a little like saying we aren’t likely to get hit by a car while crossing the street even though we can only see half of the oncoming traffic.)  

While it’s hard to wrap our minds around space dust and civilization-killing boulders hurtling through space, meteorites of an intermediate size—somewhere between, say, the pit of a cherry and a small car—are more tangible. In fact, they manage to penetrate the protective cocoon of our atmosphere several times a day, breaking into ever-smaller fragments before coming to rest on Earth’s surface. The competition to recover such cosmic remnants is stiff.  

In 2012, I met a team of professional meteor hunters in the diner of a smoky casino in the town of Battle Mountain, three hours east of Reno. Days earlier, a massive fireball had lit up the sky. A worker in a local gold mine had helped a meteorite hunter track down a grapefruit-size fragment that had nearly blindsided the miner as he worked. The leader of the team I had joined up with was a bearlike, gregarious man named Michael Farmer from Tucson, who told gripping tales of negotiating hundreds of miles of ragged, tire-shredding roads across the limestone plains of southern Australia in pursuit of a rare space rock; of having been kidnapped and beaten by a gang of criminals while on a meteorite hunt in Kenya; and having been briefly imprisoned in Oman, where he said he had run afoul of the sultan himself, who accused him of carrying out “illegal mining activity.” 

Farmer unfolded a topo map on a table covered with cups of coffee and plates of half-eaten eggs. The rock we were searching for, he explained, was known as an L6 chondrite, a fairly common class of meteorite, often containing vivid green intrusions of a mineral called olivine. Based on Doppler radar data showing the meteor’s trajectory, Farmer had sketched out a fan-shaped outline denoting the meteorite’s “strewnfield.” Though the largest piece of the meteorite had already been found, Farmer believed that the rock had shed thousands of smaller fragments across the desert as it ripped through the atmosphere. The dimensions of the search were daunting, extending over dozens of square miles in remote and rugged terrain. 

We parked in an arroyo an hour outside of town, surrounded by high plateaus and ragged monoliths. Across the sun-bleached pan, dark-colored rocks—to my untrained eye, meteoritelike in every way—lay diabolically strewn across the surface. It seemed an exercise in futility. But Farmer calmly organized us into a phalanx. Then he pointed toward the sage-stippled horizon ahead. “Stay about 10 yards apart. Go slow. I think that gives us the best chance of finding something out here.”

Within 30 minutes, the first fragment was found. “Stone!” yelled a meteorite dealer from Florida named Greg Hupé. I could hardly believe it. The team gathered to see the cherry-size rock, which looked like a briquette of charcoal dipped in fine glitter and sat suspended on a tuft of dry grass, as if it had been gently placed there by unseen hands. “I’m shaking,” said Hupé with a wide grin. 

After taking GPS coordinates, Hupé reached down with white-gloved hands to retrieve the rock, placing it gently in a specimen bag. Members of the makeshift team found three more meteorites that day. Farmer was not one of them, but he managed to work a deal the next day with a group of amateur hunters who’d found another piece of the chondrite not far from where we’d been looking.  

As the sun went down over the Nevada desert, Farmer expounded on what motivates him to travel the globe in search of strange stones. “Three weeks ago, that rock was in space, on the other side of the moon maybe, someplace you and I will never go,” he said. “There’s this indescribable joy to be the first person to touch something that has traveled millions of miles to be here.”

The meaning of meteorites may depend on the mind of the beholder, but it is, I think, tied to the fact that they provide a tangible connection to the universe beyond our own small planet. They are objects from beyond that we can touch and hold as we marvel at the depth of the cosmos.