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

An amateur astronomer searching satellite maps for possible camping locations in Quebec ended up spotting something far more unusual: evidence of a previously unrecognized impact crater.

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.

In 2024, Jo l Lapointe was preparing for a trip to the remote C te-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.