Meteor crater more than 2.2 billion years old

The oldest asteroid impact crater on Earth in the town of Yarrabubba has a diameter of up to nearly 70km.

Meteor crater more than 2.2 billion years old
Yarrabubba crater in Western Australia. (Photo: ABC).

The team from Curtin University in Perth used isotope analysis for the first time to accurately date the 69.2km-wide impact crater. The crater at Yarrabubba appeared 200 million years earlier than the second oldest crater on Earth at Vredefort, South Africa. The team, led by Dr. Timmons Erickson of NASA’s Astromaterials Research and Discovery Science Division, published the findings January 21 in the journal Nature Communications.

The Yarrabubba crater is located between the towns of Sandstone and Meekatharra in central Western Australia. Previously, researchers recognized this as a structure made of impact forces, but were unable to determine its exact age, according to Professor Chris Kirkland at Curtin University. The Earth’s surface is constantly changing due to geological tectonics and erosion processes, making the old craters very difficult to recognize.

The team analyzed zircon and monazite , two minerals that recrystallized under the influence of a meteorite impact at the bottom of the Yarrabubba crater. Dating back to 2.2 billion years, Yarrabubba is half as old as Earth (4.5 billion years). The collision also contributed to the Earth’s escape from the ice age, and the atmosphere and oceans became richer in oxygen.

The team’s calculations show that the force on the frozen continent can shoot half a trillion tons of water vapor into the atmosphere, helping to change the Earth’s climate and create a giant crater that still exists today. .