Joël Lapointe wasn’t looking for what he discovered when he opened Google Maps. He was simply planning a camping trip in Quebec’s remote Côte-Nord region. But a glance at the satellite view near Marsal Lake revealed something unexpected: a strange, ring-shaped formation that could hold clues to a cosmic event millions of years old.

Lapointe’s find — an unusual pit spanning 15 kilometers — has since sparked the attention of geophysicists, who believe the site may be the result of an ancient asteroid impact.

A Chance Discovery

After spotting the suspiciously perfect circular shape, Lapointe contacted Pierre Rochette, a geophysicist from the Centre de recherche en géosciences de l’environnement (CEREGE) in France. Together with a team of experts, Rochette examined the site more closely. The preliminary data suggested an impact event may indeed have created the ring of small mountains that circle Marsal Lake.

“Looking at the topography, it’s very suggestive of impact,” Rochette told CBC.

While some craters are easily identified by gravity anomalies or magnetic disturbances, this site offered no such clear markers. That hasn’t dampened enthusiasm. Researchers believe that with more detailed investigation, the crater could be confirmed.

The Devastation of Asteroid Impacts

When an asteroid crashes into a planet at tens of thousands of kilometers per hour, the result is often an impact crater — an immense, bowl-shaped pit formed by shockwaves that melt and recrystallize rock. Some of Earth’s most ancient craters date back over 100 million years, providing a unique window into the planet’s geological past.

Experts like Rochette and his team have already gathered some evidence in the form of rock samples. They received samples from the site containing zircons — minerals that transform under the immense pressure of an asteroid impact. If these findings hold up, Marsal Lake could join the ranks of nearly 200 confirmed impact craters worldwide, 31 of which are in Canada.

Impact craters this large are rarely discovered, especially by chance. According to Earth scientist Gordon Osinski from Western University, circular structures are often spotted on Google Earth or Google Maps, but nine times out of ten, they turn out to be geological quirks, not craters.

However, Osinski is cautiously optimistic about Lapointe’s discovery. “It’s super exciting,” Osinski told CBC reporters. “It doesn’t happen too often.”

The last asteroid impact site of this magnitude was confirmed in 2013. The crater’s age is estimated to be between 450 and 38 million years old. This suggests it formed during a period of Earth’s history that may shed new light on ancient planetary dynamics. Meteorites carry information about the solar system’s formation. And meteorites landing on Earth help scientists better understand both the distant past and the potential for future impacts.

What’s Next?

Proving that Marsal Lake is an impact crater will require more than satellite images. Rochette’s team has already conducted some preliminary studies, but fieldwork will be essential to gather more conclusive evidence. One of the telltale signs of a confirmed impact crater is the presence of shatter cones — grooved rock formations caused by the shockwaves of an impact.

The team plans to officially visit the site in 2025, pending funding for the expedition. If shatter cones or other key indicators are found, Marsal Lake could become one of the most significant geological discoveries in recent years.

Until then, the scientific community waits. Lapointe’s discovery could open a new chapter in our understanding of Earth’s geological history — and all thanks to a casual glance at Google Maps.

The findings were described at the recent 86th Annual Meeting of the Meteoritical Society 2024.