Over 3 billion years ago, a massive space rock, comparable in size to four Mount Everests, collided with Earth, and many might think it would have caused chaos on the young planet.

Indeed, a similar event occurred more recently, about 66 million years ago, when a huge asteroid impact is believed to have led to the extinction of the dinosaurs.

However, researchers from Harvard revealed that when the meteorite S2 impacted our planet, the outcome was strikingly different. Instead of ending life, this celestial body may have created conditions that allowed it to flourish.

This doesn’t imply that the collision wasn’t devastating.

What might it have felt like to witness such an impact? Nadja Drabon, an assistant professor of Earth and planetary sciences at Harvard, paints a vivid picture:

“Imagine standing off the coast of Cape Cod, in shallow waters. It’s a calm setting with no strong currents. Suddenly, a massive tsunami arrives, uprooting the sea bed,” Drabon explained.

Drabon, who led the new study detailing the S2 impact, took a team to the Barberton Makhonjwa Mountains in South Africa to seek geological evidence of this event.

Here’s what the team discovered, as published on Monday in Proceedings of the National Academy of Sciences.

Impact evidence discovered in the Barberton Greenstone Belt

The Barberton Makhonjwa Mountains feature a geological formation called the Barberton Greenstone Belt, which has experienced eight impact events, including the collision of S2.

This is where Drabon and her students conducted their field research, trekking through mountain trails to gather and analyze rock samples embedded in the Earth’s crust.

The sedimentary samples contained chemical markers within thin rock layers that aided Drabon and her team in reconstructing the tsunamis and other catastrophic occurrences resulting from S2’s impact.

S2 impact fosters bacterial life

When people think of the aftermath of meteor impacts, they often recall the famous Chicxulub impactor, which led to the extinction of dinosaurs when it collided in what is now Mexico’s Yucatán Peninsula.

However, dinosaurs were millions of years away when S2 struck about 3.26 billion years ago. This meteorite was believed to be up to 200 times larger than the Chicxulub asteroid responsible for the dinosaurs’ extinction.

This immense size was sufficient to generate a massive tsunami that mixed ocean waters and swept debris from land into coastal areas. The impact also heated the atmosphere, caused severe boiling of the ocean’s surface, and enveloped the planet in a dust cloud, obstructing sunlight and hindering photosynthesis.

Yet, the impact had a positive aspect as well.

“Typically, we associate impact events with disasters for life,” Drabon noted. “However, this study suggests that such impacts could have had beneficial effects on life, especially during the early stages, and might have actually enabled life to flourish.”

The iron that was likely stirred from the ocean floor into shallower waters supplied nutrients that allowed resilient bacteria to thrive, leading to a surge in populations of unicellular organisms, according to Drabon’s research.

Drabon and her team plan to return to the site to unearth more secrets about how the meteorite influenced Earth’s history.