A strange circle on satellite maps turned out to be a 390-million-year-old impact crater

An amateur astronomer searching satellite maps for a Quebec camping spot accidentally discovered a massive ancient impact crater. Scientists later found shatter cones that confirmed the 25-kilometer-wide structure was blasted into Earth roughly 390 million years ago. A strange circle on satellite maps turned out to be a 390-million-year-old impact crater.

(The subtle circular shape of the Uhackatik impact structure in Quebec, with Lake Marsal near the center, is visible in this image captured on October 12, 2025, by the OLI (Operational Land Imager) on Landsat 8.). Earth has only about 200 confirmed impact structures, although geologists believe hundreds more have yet to be identified. One of those hidden structures now appears to have been found, and it is a substantial one.

The newly confirmed site was first noticed by an amateur astronomer who was planning a camping trip in Quebec. A Strange Circle on Satellite Maps In 2024, Joël Lapointe was preparing for a trip to the remote Côte-Nord region when a circular feature near Lake Marsal caught his attention on online satellite imagery. He wondered whether the depression could have been formed by an impact and reached out to specialists in Europe and North America.