The Pilbara region of Western Australia is big, dry, and wide open. And it may contain the oldest cosmic “scar” on Earth: an impact crater gouged three and a half billion years ago.

Scientists discovered evidence of the crater during a brief expedition in 2021. They found some rock formations called shatter cones. Some of the cones are as tall as a house. The only known way to make them is in giant collisions with space rocks.

Follow-up work last year revealed many more of these formations. The cones were found in a rock layer that’s miles wide, but only a few dozen feet thick.

The layer also contains tiny “beads” that formed when molten rock was blasted high into the sky. The flight through the air sculpted droplets of the molten rock into balls.

Geologists found that the layer formed three and a half billion years ago, so that’s when the impact must have taken place – more than a billion years earlier than the previous record holder.

The asteroid could have been miles wide, and blasted a crater more than 60 miles across. The effects of the collision would have been felt around the world.

In fact, researchers say the impact could have helped shape the world. Major asteroid impacts could have traveled deep, churning things up far below the surface. That could have created the “seeds” that gave birth to the continents when Earth was young.

We’ll talk about potential future impacts tomorrow.

Script by Damond Benningfield