On February 15, 2013, a luminous object trailed across the skies above the Russian city of Chelyabinsk, in the southern Urals. It was around 9:00 am, just after the late winter dawn. The recent popularity of dashcams in Russia—useful in case of an accident or an encounter with the corrupt traffic police—meant that the event was filmed by many of the cars on the road that morning. Soon anyone with an Internet connection could watch a ball of fire arc toward an Orthodox church as a driver muttered obscene variations on the question “What is that?” Other videos captured an earth-shaking sonic boom. Windows broke, people screamed, alarms wailed, dogs barked. About 1,500 people were injured, mostly by shattered glass, but no one was killed.

A little more than a century earlier, at about 7:15 on the morning of June 30, 1908, another bright, mysterious object fell from the sky in a remote area of Siberia, near the Stony Tunguska River. The celestial body was similar in appearance to the one that fell in Chelyabinsk, but this time the only witnesses were a few Evenki herders and hunters, indigenous people of the region. A woman named Akulina was sleeping in her suede-covered tent when she was awakened by a violent tremor. When she stepped outside, the forest was on fire. She heard a crashing sound, saw a dazzling light, and fainted. When she regained consciousness, her possessions were smoldering and her skin was burned. Her husband’s arm was broken by a falling tree as he investigated the damage. During their slow journey through the forest to the nearest encampment, he died, probably of sepsis.

Ivan Aksenov was carving an elk he had just killed when he saw a flaming orb flying toward him. After he came to, he saw that he was surrounded by burning, falling trees. As he made his way through the landscape, first to return to camp and then to try to extinguish the fire, he no longer recognized his familiar hunting grounds; everything had been rearranged, mountains shifted and wetlands unsettled so that new lakes filled depressions in the ground.

Nearly eight hundred square miles of boreal forest had been flattened, and entire herds of reindeer were left in charred piles. The explosion’s effects were seen and felt around the world. A man forty miles away was thrown from his chair, his shirt so hot that he thought it had caught fire. One distant witness reported seeing “pillars of fire with the rising sun.” As far away as England, observers wondered at the sun’s rusty halo. But no one seriously investigated the incident until the late 1920s. The boggy forest surrounding the explosion site was forbidding and virtually unmapped, and Russia was in the early stages of the upheaval that led to the 1917 revolution.

The Tunguska event, as it came to be known, involved probably the largest meteorite to reach Earth in recorded history. The much smaller Chelyabinsk meteorite was the largest since Tunguska. In 2013 the plentiful video footage became an instant source of international amazement and amusement (Why were the Russian drivers so calm?), and part of the meteorite was soon retrieved from a nearby lake. Because the Tunguska explosion happened in an area so sparsely populated, in a time before cell phones, dashcams, and computer modeling, it became a cosmic detective story.

In Tunguska: A Siberian Mystery and Its Environmental Legacy, Andy Bruno, an environmental historian who specializes in Russia and the Soviet Union, probes this legendary story from several directions. His account raises an array of questions about how such a mystery can stimulate not only scientific research and environmental conservation but also fantasy, from pseudoscience to ufology to science fiction. The Tunguska event figures prominently in serious works of dystopian and paranoid literature too, including Vladimir Sorokin’s Ice Trilogy and Thomas Pynchon’s Against the Day. Most intriguingly, the saga shows how people cope with the prospect of the end of the world.

From the beginning the Evenki were inclined to keep news of the explosion to themselves. Their nomadism and remote location had helped them to escape taxation and avoid full subjugation to the Russian Empire, and they preferred not to call attention to themselves. They were particularly wary of outsiders examining rocks, as the discovery of gold could mean that they would be displaced from their ancestral lands. In the autumn of 1908 Aksenov and a local merchant went back to examine the destruction at the site. After their trip they warned other Evenki not to speak about the explosion, which might attract dangerous curiosity. Some Evenki spoke about the event as an act of Ogdy, a spirit in their animist belief system. According to one version of the story, rival shamans had been fighting with the help of disease-bearing spirits, and now one of the shamans had called on Ogdy to destroy enemy land with a flock of iron birds. This was the source of the fiery orb and the thousands of acres of flattened forest.


But these reports are secondhand, and Bruno observes that we will probably never know what the Evenki really thought about the explosion. Their stories were collected in the 1920s by a Soviet ethnographer as part of a concerted effort to better understand the “small peoples” who were, as the plan went, soon to be remade as productive citizens. Soviet ethnography offers a wealth of information about traditions that would soon be nearly extinguished by coercive Soviet modernization. (Two Evenki figures central to the Tunguska exploration were arrested and killed during Stalin’s purges.) But these ethnographies were often manipulated for political reasons. They suffered not only from the long-standing ethnographic problem of paternalism but also from the more particular obstacles of state-mandated atheism and Communist teleology. Akulina’s description of the event, for instance, was edited to downplay references to Ogdy, which would have compromised Akulina’s fledgling career as a Soviet activist.

The explosion might have been lost in the billowing smoke of World War I, the Russian Revolution, and the Russian Civil War if not for Leonid Kulik, whose sleuthing in the 1920s helped make Tunguska, in Bruno’s words, “a famed riddle of twentieth-century science.” As a young man Kulik was an ardent revolutionary, and he became a scientist to fund this political vocation. When the Tunguska explosion occurred he had recently started work as a forester in the Urals, though he soon moved on to mineralogy. In 1918 he was sent to study an impact site in the Tver region where a meteorite had fallen, and his second lifelong passion was born. This meteorite was an easy one: it had been located before he arrived. At the time, scientists were in the early stages of understanding how rocks could arrive on Earth from outer space after breaking off from asteroids, the rocky detritus of the formation of our solar system.

The more mysterious Tunguska explosion was irresistible to a meteorite enthusiast, though merely reaching the site was a daunting logistical challenge. When Kulik first ventured there in late winter 1927, he was entirely dependent on indigenous knowledge and assistance as he made his way through the swampy, mystifying forest. “All elements of our geographic maps are so conditional,” he complained, “that it would perhaps be more accurate if this whole area was designated by a continuous white spot.” One of his guides was an Evenki hunter named Liuchetkan, the brother of Akulina’s late husband; Liuchetkan and Akulina had already discovered a potential crater, a deep furrow and pit near the epicenter of the explosion.

The ethnographer who introduced Liuchetkan to Kulik offered advice on how to avoid offending the Evenki or arousing their suspicions. “Don’t mention the local Soviet Cultural Base,” he warned, “and if you collect rocks, pretend they’re mementos.” But the stubborn Kulik had little respect for others, including the Evenki who guided him through the bewildering landscape and kept him from starving or freezing in the forest. He berated them for taking too long for their tea breaks. Offended, Liuchetkan demanded a higher fee.

Nevertheless, Kulik did make it to the edge of the site with the help of the Evenki and a herd of reindeer that hauled their provisions. He was astonished by his first sight of the trees. “The entire large forest in the mountains had tumbled onto the ground in solid rows,” he observed. “In the valleys not only did the ripped-out roots stick up, but so too did the broken trunks.” The Evenki refused to continue to the epicenter, which they considered dangerous and perhaps cursed, and Kulik was wise enough to know that he could not survive without them. The group turned back, and he had to wait to reach the epicenter until late April, when he found non-Evenki to accompany him to the place mapped by Liuchetkan.

On this second, closer inspection, Kulik saw that the fallen trees were oriented outward from a central point; perhaps this was the place the meteor had hit. His return this time was especially difficult. Having ignored advice about the dearth of game in the area thanks to the destruction of the forest, he had to survive largely on the stems of herbs and—according to later Tunguska researchers—may even have resorted to eating his horse.

Liuchetkan and others continued to provide the obnoxious Kulik with clues, telling him about changes they had observed in the landscape, like an area where the land was wetter and lower than it had been before the explosion. The cold and malnourished Soviet scientists on Kulik’s expeditions, meanwhile, descended into drunken brawls and affairs with locals. One member of the team carved a poem into a tree at the epicenter:


In vain, Kulik, you wander,
In vain you tear out the sphagnum,
You will not see a meteor
And you will leave the taiga in shame.

This disgruntled investigator and another colleague, a member of the Communist Party, denounced Kulik—who wouldn’t share his chocolate or coffee with his team—to the authorities. Kulik managed to defend himself successfully, with other colleagues speaking up for him, but he had to spend several months in a sanatorium to recover from the stress of the denunciation combined with the cumulative health effects of his many expeditions. Some of the most common trials endured by researchers included scurvy and boils from malnutrition, frostbite, and insect bites that swelled grotesquely.

For all his willingness to destroy himself for his research, Kulik never found a crater or even a confirmed fragment of the meteorite. In desperation, he killed birds and cut them open to look for traces of space rock. The charitable Bruno calls him a “Sherlock Holmes of the taiga,” but at times he sounds more like a boreal Inspector Clouseau—for instance when he finds a piece of glass that he believes to be an impactite, a rock made or changed by a meteorite’s fall, only to realize that it’s a shard of a bottle melted in a campfire. Even after years of research at the site, the team was often hapless. When two researchers watched their horse drown in a bog, taking with it their equipment, they wandered the forest for several weeks, unable to find their way. When they finally encountered an Evenki herder, he assigned one of his reindeer to escort them to safety while he continued on his business with the rest of his herd.

But Kulik and his associates were clever fundraisers. Their greatest public relations coup was their decision to recruit the tabloid press to write alarmist articles about the prospect of Kulik dying in the wilderness unless he received more money for research. (Academics, take note.) Now Kulik became, as Bruno puts it, “a Robinson Crusoe of the taiga.” One journalist dubbed him a “hero-scholar.” Reports of his plight were spiced with invention, including a story about bandits out for his blood. This only made the stories more popular. A children’s board game called In the Taiga for a Meteorite went on sale in 1929, the same year a documentary about the expedition was released.

Tunguska became an object of widespread fascination, thanks to its combination of mystery, rugged wilderness adventure, and hints of the otherworldly and apocalyptic. Tunguska enthusiasts were transfixed by images and descriptions of the site, the “land of the dead forest,” as one researcher described it in a poem:

It sings a triumphant song over the taiga.
Over the power that rests in it,
At times it sings a requiem,
Performing a funeral ceremony.

The expanse of burned, flattened trees suggested a gloomy yet sublime danger, the possibility that the world could be annihilated in an instant. Akulina’s story of awaking to a scene of utter, unimaginable destruction resembles a standard opening of a postapocalyptic tale. The healthy forest that resumed at the edge of the site, meanwhile, was a sign of grace, a reprieve. This time the heavenly body was not large enough to cause a mass extinction.

The elusive meteorite held a particular appeal in an era when the Soviets were dreaming of space, with varying levels of scientific realism. In the relatively free 1920s, Soviet science fiction was booming, soon to be renamed “scientific fantasy”—an apt revision since the genre was often written by real scientists. Scientific fantasy was a cousin of the political utopian novel, another important form for revolutionaries; fiction was not only the terrain of imagination but a place to hash out new hypotheses and new ways of living. The period teemed with fantasies of conquering time, death, and capitalism, of creating utopias in outer space as well as on Earth. But these dreams were shadowed by the prospect of mass destruction—a specter that loomed large after years of war, revolution, and famine.

After the American atomic bombs dropped on Hiroshima and Nagasaki, visions of the apocalypse gained a new vocabulary and a new scale. Kulik died in 1941, at the age of fifty-eight, in a Nazi prisoner-of-war camp. Many of his successors in the investigation searched not for a simple meteorite but for evidence of a nuclear blast. One of their inspirations was a short story by an engineer named Alexander Kazantsev. As he brooded over descriptions of one of the explosions in Japan, he realized that it reminded him of Tunguska, with its

blinding sphere brighter than the sun, the fiery column that pierced the clouds, the dark mushroom above it, the roars of thunder heard for hundreds of kilometers, and the earthquake and shockwave that two seismographic stations picked up.

What if that had been an atomic explosion, too—and what if it had been caused by a nuclear-powered alien spacecraft?

In January 1946 Kazantsev published a short story about the scenario, entitled “Explosion.” He then adapted it into a performance at the Moscow Planetarium, with the help of one of Kulik’s former colleagues, in hopes of reawakening interest in the Tunguska event after it had slipped from government and public interest in the 1930s. Felix Zigel, an astronomer, lectured the auditorium on the history of the Tunguska meteorite, after which actors pretending to be audience members asked questions suggesting that the explosion had come from a nuclear spacecraft from another planet. The performance persuaded many audience members of the alien theory—including Kazantsev, who began to believe his own fiction.

A heated debate in journals soon followed, a muddle of scientific, pseudoscientific, and ideological arguments. Scientists overshot in their attempts to squelch Kazantsev’s idea, asserting absolute certainty, for instance, that a meteorite had landed on Earth and would eventually be found. This later undermined their authority. Bruno points out that the debate coincided with the “nadir of Stalinist science,” the year when the theories of the charlatan biologist Trofim Lysenko were declared Soviet doctrine. Many of Lysenko’s scientific critics had already been executed or imprisoned; now the field of genetics was essentially banned, replaced by his bogus theory of heredity as determined primarily by external conditions.

Lysenko’s scientific fantasy found favor in large part because it aligned with Soviet faith in the infinite malleability of all things—even plants—under communism. Such egregious politicization of science is easy to mock, but it is uncomfortably familiar in the United States today, as is the unhappy dynamic among right-minded scientists, charlatans, and conspiracy theorists. The uncertainty inherent in the scientific method can make it hard to defend from those who have been carried away by their own imagination, or by someone else’s. Doubt is easy to exploit.

Zigel went on to become, in Bruno’s words, “a founder of Soviet ufology,” a lesser-known parallel to the American postwar craze for flying saucers. On both sides of the Iron Curtain, the obsession with UFOs and alien visitations was a clear response to the atomic bomb and the cold war, with all the attendant fear of the foreign enemy and anxiety about secrets being kept by one’s own government. Locked in the embrace of mutually assured destruction, both sides lived in fear that their worlds could be reduced to ashes at the touch of a button. Schoolchildren were subject to nuclear bomb drills even more useless than the active shooter drills that American children now endure.

Preoccupation with extraterrestrials was a displacement of these fears, and a deflected memory. The imagined alien conquerors resembled a googly-eyed revision of the colonialism that had shaped both American and Russian history: a technologically advanced society arrived from a distant land to take whatever resources it desired and impose its own rules on its new subjects. But the thought of aliens could also be hopeful, even utopian. Rather than hostile invaders, aliens might be benevolent new friends. The most optimistic ufologists hoped that the visitors would save humankind from itself and usher in a new era of cooperation, an intergalactic version of the kind of utopian vision that had helped create the Soviet Union.

Or maybe the extraterrestrials weren’t aliens at all. Perestroika made it easier for foreigners to join in the Tunguska investigation. The first to visit was a group from Japan who viewed the site not as evidence of extraterrestrial life but as a graveyard of their ancestors. They believed that several millennia ago, a Japanese society discovered the secrets of nuclear power and spaceflight. When they tried to come back to Earth, they crashed at Tunguska. Visiting the site was a way of honoring these lost ancestors and perhaps reuniting with them in some way. This fantasy had something in common with the musings of the proto-transhumanist Russian philosopher Nikolai Fedorov, who in the late nineteenth century imagined that one day science would allow us to resurrect every human who ever lived, reassembling the most distant ancestors from dust scattered across the solar system. Fedorov’s wacky techno-optimism is a forerunner of today’s billionaire fantasies of living forever and escaping climate change by moving to outer space.

The Chelyabinsk meteorite helped put to rest many of the remaining questions about the Tunguska event, though scientists continue to propose novel hypotheses, and conspiracy theories no doubt still lurk in the darker reaches of the Internet. Using computer modeling, scientists concluded that the Chelyabinsk meteorite was most likely a stony asteroid about sixty-six feet in diameter that fragmented fifteen miles above the surface of Earth, causing a shock wave similar to that of a 550-kiloton explosion. It is estimated that meteors of this scale hit Earth every ten to one hundred years. The Tunguska object, meanwhile, was probably a stony asteroid between 164 and 262 feet in diameter. It entered the atmosphere at about 34,000 miles per hour, generating the energy of a ten- to thirty-megaton explosion, comparable to a major volcanic eruption, when it was six to nine miles above the ground. Kulik never found a crater or a meteorite because the meteorite exploded in the air.

Fortunately, computer modeling suggests that such an impact is likely to occur only once every several millennia. Bruno writes with an eye to anthropogenic climate catastrophe today, when the fear of asteroid-related apocalypse seems almost quaint. There is something oddly soothing about his reflection near the end of the book that earthlings have at best another billion years until the sun begins to draw Earth into its inferno, the oceans evaporating and our planet left lifeless long before “our middle-aged star bursts into a red giant and then extinguishes itself as a white dwarf.” In the worst-case scenario, our whole planet could vanish tomorrow: “A process called vacuum decay could theoretically strike at any moment, pulling apart the particles that make up visible matter, including everything on our planet, in a flash.” At least it wouldn’t be our own fault.