{"it":{"id":"ART017","kind":"artifact","sub":"Authenticated","name":"Tunguska event","place":"—","date":"30 June 1908","mat":"airburst (no artifact)","dims":"2,150 ± 50 km² continuous treefall (1958-65 expeditions); \"80 million trees\" is from an…","loc":"—","acc":"—","flag":"genuine ancient","src":[149,150,151],"tags":[],"sum":"At about 7:15 in the morning on 30 June 1908, something exploded in the sky over a remote part of Siberia. Evenki reindeer herders saw a fireball and felt the blast. The shock wave flattened trees across a butterfly-shaped area of about 830 square miles.\n\nThe region was so remote that no scientist reached it for years. Leonid Kulik tried in 1921 and failed. He arrived in 1927 and found trees laid flat, while trees near the centre still stood, stripped of branches like telegraph poles. NASA says the object exploded 6 to 10 km up, over what is now the Evenkiysky district of Krasnoyarsk Krai.\n\nWhat is hard to explain is the lack of a crater. Kulik searched for a meteorite and found none, and microscopic particles in the soil have not been tied to the object with certainty.\n\nThe mainstream answer is an airburst. NASA's history office describes a bolide perhaps 130 feet across, entering at about 30 degrees and exploding in mid-air, its body vaporised before it reached the ground.\n\nA blast this large left no hole. How many others have struck without a trace?","why":"An explosion over Siberia in 1908 flattened millions of trees and left no crater.","nfacts":0,"nsrc":3,"yt":"Map the treefall pattern.","rel":["W15A04"],"hook":"On 30 June 1908 a blast over Siberia flattened 830 square miles of forest and left no crater."},"S":{"149":["en.wikipedia.org","https://en.wikipedia.org/wiki/Tunguska_event"],"150":["tunguska.tsc.ru","https://tunguska.tsc.ru/ru/science/1/bron/10br/"],"151":["doi.org","https://doi.org/10.1038/s41598-025-98362-9"]},"rec":{"id":"ART017","alias":[],"ms":[],"lab":[],"eng":[],"ori":[],"gaps":[{"a":"find_circumstances","r":"not in staged/legacy artifact record (free sources)"}],"dat":[],"aa":[{"id":"AA096","a":"Crashed alien craft / Tesla","who":"popular AA literature/TV","main":"Airburst of stony asteroid or comet fragment","ms":"https://en.wikipedia.org/wiki/Tunguska_event ; https://tunguska.tsc.ru/ru/science/1/bron/10br/ ; https://doi.org/10.1038/s41598-025-98362-9 ; https://en.wikipedia.org/wiki/Tunguska_event","st":"contradicted","n":"status from artifacts row; no new lab rows this batch","nl":1}],"ac":[],"me":[],"ci":[],"cq":[],"sd":[],"art":{"claimed_anomaly":"Crashed alien craft / Tesla","mainstream_reading":"Airburst of stony asteroid or comet fragment","provenance_flag":"genuine ancient","current_location":"","find_circumstances":"","claimant":"","status":"","dimensions":"2,150 ± 50 km² continuous treefall (1958-65 expeditions); \"80 million trees\" is from an 8,000 km² preliminary estimate","material":"airburst (no artifact)","date":"30 June 1908","culture":"—","museum_accession":"—","b":"V","s":[]},"sub":[],"src":[{"id":"S0625","t":"en.wikipedia.org","u":"https://en.wikipedia.org/wiki/Tunguska_event"},{"id":"S0674","t":"tunguska.tsc.ru","u":"https://tunguska.tsc.ru/ru/science/1/bron/10br/"},{"id":"S0057","t":"doi.org","u":"https://doi.org/10.1038/s41598-025-98362-9"},{"id":"VART017-4","t":"NASA History: 115 years ago, the Tunguska asteroid impact event","u":"https://www.nasa.gov/history/115-years-ago-the-tunguska-asteroid-impact-event/"},{"id":"VART017-5","t":"NASA Earth Observatory: A cosmic explosion over Siberia","u":"https://science.nasa.gov/earth/earth-observatory/a-cosmic-explosion-over-siberia-154488/"}],"qs":["A blast this large left no hole. How many others have struck without a trace?","Would we spot an object like this before it arrived today?"],"gal":[{"src":"https://thumb.wikimedia.org/wikipedia/commons/thumb/a/a4/Tunguska_Ereignis-1.jpg/1280px-Tunguska_Ereignis-1.jpg?utm_source=commons.wikimedia.org&utm_campaign=imageinfo&utm_content=thumbnail","page":"https://commons.wikimedia.org/wiki/File:Tunguska_Ereignis-1.jpg","title":"Tunguska Ereignis-1.jpg","lic":"Public domain","licurl":"","by":"Leonid Kulik, the expedition to the Tunguska event","cap":"Tunguska event. Trees were knocked down and burned over hundreds of square km by the Tunguska meteoroid impact. This image is cropped from the original, taken i"},{"src":"https://thumb.wikimedia.org/wikipedia/commons/thumb/9/97/JohnStone.jpg/1280px-JohnStone.jpg?utm_source=commons.wikimedia.org&utm_campaign=imageinfo&utm_content=thumbnail","page":"https://commons.wikimedia.org/wiki/File:JohnStone.jpg","title":"JohnStone.jpg","lic":"CC BY 4.0","licurl":"https://creativecommons.org/licenses/by/4.0","by":"Cmbrenneisen58","cap":"Thin section of a fragment of \"John's stone\" from the epicenter of the Tunguska event. \"John's stone\" was suspected of being a Tunguska meteorite fragment, but ","alt":"Thin section of a fragment of \"John's stone\" from the epicenter of the Tunguska event. \"John's stone\" was suspected of being a Tunguska meteorite fragment, but"},{"src":"https://thumb.wikimedia.org/wikipedia/commons/thumb/a/a3/Melanonyx_neglectus_Alpheraky.jpg/1280px-Melanonyx_neglectus_Alpheraky.jpg?utm_source=commons.wikimedia.org&utm_campaign=imageinfo&utm_content=thumbnail","page":"https://commons.wikimedia.org/wiki/File:Melanonyx_neglectus_Alpheraky.jpg","title":"Melanonyx neglectus Alpheraky.jpg","lic":"Public domain","licurl":"","by":"Frederick William Frohawk","cap":"Melanonyx neglectus = Anser neglectus"},{"src":"https://thumb.wikimedia.org/wikipedia/commons/thumb/0/0d/Moscow_State_University_Tunguska_event_2014-01_1389528710.JPG/1280px-Moscow_State_University_Tunguska_event_2014-01_1389528710.JPG?utm_source=commons.wikimedia.org&utm_campaign=imageinfo&utm_content=thumbnail","page":"https://commons.wikimedia.org/wiki/File:Moscow_State_University_Tunguska_event_2014-01_1389528710.JPG","title":"Moscow State University Tunguska event 2014-01 1389528710.JPG","lic":"CC BY 4.0","licurl":"https://creativecommons.org/licenses/by/4.0","by":"Artyom Svetlov","cap":"Tunguska event"},{"src":"https://thumb.wikimedia.org/wikipedia/commons/thumb/c/c7/Osharovo_settlement_on_the_Podkamennaya_Tunguska_River.jpg/1280px-Osharovo_settlement_on_the_Podkamennaya_Tunguska_River.jpg?utm_source=commons.wikimedia.org&utm_campaign=imageinfo&utm_content=thumbnail","page":"https://commons.wikimedia.org/wiki/File:Osharovo_settlement_on_the_Podkamennaya_Tunguska_River.jpg","title":"Osharovo settlement on the Podkamennaya Tunguska River.jpg","lic":"CC BY-SA 3.0","licurl":"https://creativecommons.org/licenses/by-sa/3.0","by":"ShavPS","cap":"Osharovo settlement on the Podkamennaya Tunguska River, view from a helicopter (Evenkiysky District, Krasnoyarsk Krai, Russia)"}],"sum":"At about a quarter past seven on a summer morning in 1908, a few Evenki reindeer herders in the forests of central Siberia looked up and saw a ball of fire crossing the sky, trailing smoke. Then came a flash brighter than the sun, and a noise like thunder. Those closest were thrown into the air and knocked senseless. Their dwellings were damaged or torn apart. Further away, people watched a great column of smoke climb high into the atmosphere, and hundreds of miles off, seismic instruments trembled as the shock wave passed through the ground.\n\nWhen the smoke cleared, an area of forest larger than many cities lay flat. Millions of trees had been knocked down like matchsticks, all pointing away from a single centre. And at that centre, where you would expect a crater, there was none.\n\nThis is the Tunguska event, and more than a century later the thing that caused it has still not been found.\n\nIt happened on 30 June 1908, while Tsar Nicholas II ruled Russia, over one of the remotest places on Earth, today the Evenkiysky district of Krasnoyarsk Krai. Because so few people lived there, very few human deaths were recorded, though there were reports of whole herds of reindeer killed. That same remoteness meant the event drew only brief attention, even inside Russia, and almost none outside it.\n\nThe size of what happened only emerged slowly. Surveys in the 1950s and 1960s, by professional scientists and volunteers, mapped a zone of destruction shaped like a butterfly, covering about 830 square miles and reaching between nine and 22 miles from its centre. Expeditions between 1958 and 1965 measured continuous treefall over about 2,150 square kilometres. The often-quoted figure of 80 million trees comes from an earlier, rougher estimate that covered a much larger area of some 8,000 square kilometres. Either way, a forest had been felled in an instant.\n\nThe first scientist to try to reach it was the mineralogist Leonid Kulik, sent by the Soviet Academy of Sciences in 1921. He failed; the land was too wild to cross. Nearly twenty years passed in all before anyone arrived, years swallowed by the First World War, the Russian Revolution and the civil war that followed. Kulik finally reached the site in 1927. Even after nineteen years the wound was plain. Around the edges, trees lay flattened in a radial pattern, like spokes of a wheel. But near the centre they still stood upright, burned, their branches broken and their bark stripped away, so that they looked like a forest of telegraph poles. Kulik came looking for a meteorite, and through expeditions into the 1930s, with photographs and aerial surveys, he searched for the stone that had done this. He never found it.\n\nThere is a lesson in Kulik's long hunt about what people expect to find. A meteorite was the obvious answer, the kind of thing a scientist could hold up and name. The forest was offering a different answer: whatever had come, it had not arrived in one piece.\n\nThe mainstream explanation, which most scientists accept today, is an airburst. NASA's history office describes a bolide, the name for an asteroid once it is burning through the atmosphere, perhaps 130 feet across, coming in at an angle of about 30 degrees. NASA's Earth Observatory puts the object at 50 to 100 metres across and the explosion at about 6 to 10 kilometres up. At that height the object exploded in mid-air, and most of it was vaporised before it could reach the ground. Its shock wave and heat, NASA says, most likely account for what the herders described and what the later expeditions found. Smaller asteroids, NASA notes, break up in the atmosphere regularly, usually causing little or no harm. Tunguska was simply a large one.\n\nThat account explains the shape of the damage well. What it has not yet done is produce the object.\n\nThe evidence for what struck Siberia remains surprisingly thin. Later expeditions found microscopic particles that pointed to an origin beyond the Earth, but they could not be tied to the blast with certainty. Researchers have pointed to rock fragments, shocked quartz and irregular tree rings as possible traces. Some proposed that nearby Lake Cheko was gouged out by a falling fragment; other teams dispute that. Even the path of the incoming object is uncertain, with published trajectories that vary considerably. For a while scientists argued over whether it was a comet or an asteroid, and though most now favour an asteroid, NASA's Earth Observatory states plainly that direct evidence of a crater or of the object itself remains elusive and is still debated. A Landsat satellite photographed the area in July 2024. It shows healthy pine forest, marshes and rivers. The scar has healed so completely that, from orbit, nothing seems to have happened at all.\n\nTunguska changed how the world thinks about the sky. NASA now runs a Planetary Defense Coordination Office, and its DART mission tested a way to nudge a small asteroid off course. The United Nations declared 30 June International Asteroid Day in its memory. NASA's database held more than 38,000 known near-Earth asteroids by June 2025, and the count is climbing fast.\n\nBut the deeper puzzle is not about defence. Something from beyond the Earth arrived over Siberia with the force to flatten two thousand square kilometres of forest, and then, in effect, disappeared. It left a shape on the ground, a set of burned poles, a few disputed particles, and a lake no one can agree on. If an event this enormous, in the twentieth century, with scientists searching for decades, can leave so little behind, what does that tell us about how much the ancient record could be missing?\n\nHow many visitors from the sky have come and gone, and left no trace at all for us to find?"},"img":null,"md":null,"hh":[{"v":"500","u":"kt","h":"Energy released by an asteroid of ~11,000 tons","s":[240]},{"v":"30 June 1908","h":"Date","s":[241]},{"v":"Airburst","h":"Made of: Airburst (no artifact)","s":[241]},{"v":"—","h":"Held at","s":[241]}],"hs":{"240":["Wikipedia: Tunguska event (and sources cited there)","https://en.wikipedia.org/wiki/Tunguska_event"],"241":["en.wikipedia.org","https://en.wikipedia.org/wiki/Tunguska_event"]},"lh":{"s":"img/h/ART017.webp","w":1280,"h":869,"o":"https://thumb.wikimedia.org/wikipedia/commons/thumb/a/a4/Tunguska_Ereignis-1.jpg/1280px-Tunguska_Ereignis-1.jpg?utm_source=commons.wikimedia.org&utm_campaign=imageinfo&utm_content=thumbnail"}}