In the summer of 1908, Semen Semenov sat down to breakfast on a porch in Vanavara, a remote town in Krasnoyarsk, Russia. The Siberian sun offered scant warmth as the day began. Far to the north, a blue light split the sky, and flames swept through the trees along the river forest. Semenov felt heat creep over his body as if he had stepped into another realm. He fought to tear off his shirt while a roaring sound erupted from the forest and a powerful force hurled him several meters, slamming him into a wall and sending him unconscious. A violent tremor, accompanied by a high-pitched clatter, shook the house and rattled crops and roads. A scorching wind swept through the village, leaving damage in its wake.
Semenov’s experience echoed the memories of many Siberian residents at the dawn of the twentieth century. His testimony became part of the record that Russian scientist Leonid Kulik would later document in 1930, showcasing one of the most substantial eruption narratives in human history.
Location of the place where the event took place
What happened? On June 30, 1908, villages near the Tunguska River in the Krasnoyarsk region were struck by an explosion that felled about 80 million trees across roughly 2,150 square kilometers, an area larger than the entire island of Tenerife. The shock traveled widely, and the event was felt across the globe. Seismographs recorded the sound, and two nights later the sky remained bright enough to read a newspaper outdoors at midnight in London.
It exploded in the air without touching the ground
The Tunguska mystery has spurred countless studies, yet the origin of the phenomenon remains unresolved after more than a century. Today the consensus points to a meteoric airburst, an event classified as an impact explosion even though no crater has ever been found. The most recent theories place the explosion at altitudes between 5 and 10 kilometers above the surface, far from any surface collision.
Fallen trees across the region became a key clue. The center of the eruption was inferred from the radial pattern of damaged trees rather than a surface crater. The absence of a traditional impact crater has long fueled debate and inspired numerous hypotheses and legends.
The region’s devastation was widely documented. Since 1908, thousands of scientific papers, many in Russian, have explored the event. Leonid Kulik, a Russian geologist, became the principal figure in the search for answers. His work began in 1921, and in 1927 he organized the first scientific expedition to the area, hoping to locate an impact crater that would confirm a collision with the Earth.
During those expeditions, Kulik relied on local hunters to navigate the inhospitable terrain in search of evidence. To his surprise, no crater or footprints appeared to indicate a surface impact. Instead, the expedition identified a clear epicenter—ascertained from the radial fossil patterns of the felled trees—marking a groundbreaking discovery in the study of the event.
The puzzle remains partially solved. The Tunguska disaster has long stood as a source of speculation and folklore, sometimes obscuring the clearer scientific picture. In 2004, a provocative theory suggested that an alien craft rather than a natural body caused the catastrophe, a claim met with widespread skepticism but enduring curiosity.
Or an asteroid or a comet
Today researchers consider two primary suspects: an asteroid or a comet. Expeditions in the 1950s and 1960s recovered microscopic spheres of silicate and magnetite in soil samples, hinting at an extraterrestrial source. Later analyses of peat bog samples near the central affected zone, published in 2013, identified tiny material traces consistent with a meteorite origin.
A study released in June 2020 in the Monthly Notices of the Royal Astronomical Society proposed a scenario in which a large iron asteroid entered the atmosphere at a relatively low altitude and exploded, its shock wave devastating part of the Earth’s surface while the body itself did not reach the ground. Other researchers have suggested that a lake, potentially formed by the impact, may be a wound from a low-speed fracture about 450 meters long, though evidence for the lake’s existence prior to 1928 remains contested.
Even after a century, the Tunguska event remains one of science’s most enduring mysteries, inviting ongoing inquiry and debate about what truly happened on that remote Siberian landscape.