A monumental discovery has revealed that an asteroid struck the East Coast of North America roughly 35 million years ago, leaving behind the continent’s largest known impact crater, now buried beneath the Chesapeake Bay.

The impact was so powerful that it not only created the massive crater but also unleashed catastrophic events across the region. These included enormous fires, earthquakes triggered by shockwaves, and molten glass hurled into the sky. A towering air blast and a destructive tsunami reshaped the landscapes of what are now Virginia and Maryland.

A Catastrophic Event That Changed the Landscape

According to the study, published in Meteoritics and Planetary Science, the asteroid’s collision with the Atlantic Ocean was a defining event in Earth’s history. The explosion, powerful enough to trigger fires and seismic activity, left behind a crater stretching approximately 25 miles across. Over millions of years, sediment layers gradually covered the crater, making it undetectable until the early 1990s.

Through marine geophysical surveys and drilling operations, scientists confirmed the existence of this colossal impact site, which remains the largest crater in the United States and the 15th largest on the planet.

The Ejecta and Its Global Impact

When the asteroid struck, it expelled vast quantities of material into the sky. Among the debris were tektites—glassy fragments formed from the intense heat of meteorite impacts—and zircon crystals, which were blasted by the shockwave. This airborne debris rained down over an enormous area, creating what is now known as the North American tektite strewn field.

Spanning about 4 million square miles, this ejecta blanket covered a region ten times larger than Texas. Much of the material settled on the ocean floor, but significant portions landed on land as well.

Credit: GEBCO World Map, 2014

Piecing Together the Timeline of the Impact

To better understand the impact’s scale and timing, researchers turned to samples obtained from the Ocean Drilling Project’s site 1073. Led by Marc Biren from Arizona State University, the team utilized uranium-thorium-helium dating, a sophisticated technique that helped determine the exact timing of the asteroid strike.

This method also provided insights into how long it took for the debris to cool and settle, offering a clearer understanding of one of the most violent geological events in North America’s history.

This groundbreaking research has given scientists a deeper insight into a catastrophic event that continues to shape the geological landscape of the United States, offering new perspectives on how such impacts influence both the environment and the planet’s history.