While scouting online satellite maps for a remote camping trip in Quebec, an amateur astronomer made an unexpected discovery that has added a massive prehistoric scar to Earth’s geological records. Instead of finding a suitable site to pitch a tent, Joël Lapointe stumbled upon a vast circular depression that has now been confirmed as a 390-million-year-old impact crater.
Earth currently has roughly 200 confirmed impact structures scattered across the globe, but geologists have long estimated that hundreds more lurk undiscovered beneath forests, deserts, and bodies of water. The newly identified site near Lake Marsal in Quebec’s remote Côte-Nord region stands out not only for its sheer size but also for the unusual way it came to light through the curiosity of a citizen scientist.
The discovery dates back to 2024, when Lapointe was preparing for his wilderness excursion. While examining online satellite mapping tools, he noticed a distinct circular feature near Lake Marsal. Suspecting that the unique depression might be an impact crater rather than a standard geographical feature, he reached out to geological experts in both North America and Europe to share his observations.
His inquiries caught the attention of a team of French researchers, who presented the lake area at a 2024 meeting of the Meteoritical Society as the potential location for the 11th known impact structure in Quebec. That presentation eventually drew the interest of Gordon Osinski, a planetary geologist at Western University and director of the Impact Earth database.
Although Osinski was initially skeptical of a crater being found through casual satellite map browsing, his scientific curiosity was sufficiently piqued. He decided to organize a formal scientific expedition to the remote site in October 2025 to investigate the terrain firsthand and determine its true origin.
Reaching the site proved to be a formidable undertaking. Osinski and his colleagues had to arrive by floatplane, but the aircraft could not reach the shore, forcing the researchers to wade across 50 meters of cold water while heavily laden with scientific gear. Once on land, they encountered rugged, swampy terrain teeming with insects and covered by dense vegetation that Osinski described as deep, twisty, and gnarly. Despite having conducted extensive fieldwork across six continents during his career, Osinski noted that the conditions at Lake Marsal ranked among the most challenging he had ever experienced.
Previous regional geologic mapping had suggested that the breccia rocks found in the area were the product of a funnel-shaped volcanic feature known as a diatreme, which forms as a pipeline of fragmented rock driven by explosive underground magma eruptions. However, by the second day of fieldwork, the research team found definitive proof pointing to an entirely different cataclysmic origin.
The scientists identified distinctive geological formations called shatter cones embedded in numerous rock outcrops. Shatter cones are conical fractures that develop in rocks under the extreme, unimaginable pressures of a hypervelocity meteorite impact and represent the only unequivocal evidence of an impact event that can be observed directly in the field with the naked eye.
Further analysis revealed that the impacting object was massive enough to carve out a complex crater structure spanning 25 kilometers, or roughly 16 miles. The ancient structure features a distinct central uplift and towering cliffs marked by columnar jointing. Osinski noted that if an asteroid or comet of a similar scale were to strike the region today, the event would cause regional devastation capable of wiping out major cities and triggering severe global climate impacts.
Rock samples recovered from the site indicate that the impact crater likely formed approximately 390 million years ago. This places its formation roughly 100 million years before a well-documented surge in terrestrial cratering events that scientists believe may be linked to major collisions within the asteroid belt.
Following consultations with the Innu Council of Ekuanitshit, the research team has proposed naming the newly confirmed site Uhackatik. While the investigators consider the crater’s impact origin to be firmly established, a committee of the Meteoritical Society is expected to formally recognize the site when it convenes for its next meeting. This marks the largest impact crater discovered since the 31-kilometer Hiawatha structure was found buried beneath glacial ice in Greenland in 2018.
As a member of NASA’s first Artemis Geology Team, Osinski assists astronauts with specialized geological field training. However, he does not expect to see astronauts training at Uhackatik anytime soon due to the extreme logistical difficulties of reaching the remote location. Instead, he points to a younger and far more accessible impact crater in Labrador, known as Kameshtashtan or Mistastin Lake, where astronauts have historically conducted lunar geology field training.
For Lapointe, helping bring the hidden crater to the attention of the scientific community remains an unforgettable experience. He told reporters that he was overjoyed when researchers officially confirmed his suspicions. He has since encouraged other members of the public not to ignore their intuition or unusual observations, even when examining phenomena far outside their primary professional fields of expertise.
For other citizen scientists and astronomy enthusiasts hoping to contribute to planetary science, space agencies continue to offer numerous public participation initiatives. Programs like NASA’s Daily Minor Planet allow volunteers to assist researchers in scanning data for asteroids and comets that could potentially cross paths with Earth. Other projects, such as Impact Flash, invite the public to scour dark regions of the Moon for sudden flashes caused by incoming meteoroid impacts, while Exoasteroids provides avenues to search for debris disks and asteroid signatures orbiting distant stars beyond our Solar System.
