Earth is no strangers to asteroids, hitting its surface and shaping its history. While not all ancient asteroid impact events devastated everything, but instead created the Earth-Moon system, shaped the evolutionary history of life, the origin of water on Earth, some of them led to several mass extinctions. One of the most famous events is the prehistoric Chicxulub impact that happened 66 million years ago, which caused the Cretaceous-Paleogene extinction event when all dinosaurs disappeared.
In the 1990s, during scientific drilling, scientist discovered an impact crater on the East Coast of North America, under which is now called the Chesapeake Bay. After much investigation, the researchers determined that the crater was formed after an asteroid hit Earth 35 million years ago.
The shock of the impact most likely created fires, earthquakes, tsunamis, hot air blast, and falling molten glass droplets. It is the most prominent impact crater in the U.S. and the 15th biggest on the planet as it is 25 miles (almost 40 km) in diameter.
Ancient Asteroid Impact Crater Found In The United States
The collision also created an impact ejecta layer comprised of tektites and shocked zircon crystals. The tektites are glass that forms naturally from debris after an asteroid impact. The shock ejected these materials on an area of 4 million square miles (10,360,000 square km) around the impact crater, not only on the ground but also in the ocean.
A team of researchers succeeded in retrieving samples of the ejecta materials from the ocean floor with the help of a method called the uranium-thorium-helium dating. The zirconium crystals were the most important ones as they conserve proof of the shock metamorphism, which could give the scientist more information about the impact.
The study of such impacts, whether craters, pieces of the asteroid or materials formed after the collision, help researchers understand more about Earth’s past and how life continued after such calamities. The results of their findings have been published in the journal Meteoritics & Planetary Science.