Researchers find 3.5 billion-year-old meteorite crater in Australia

Researchers have found an ancient impact crater in Western Australia. It is the oldest currently known and could provide new insights into the origin of life on Earth.

The crater is located in North Pole Dome in the Pilbara region of Western Australia. According to the team from Curtin University in Perth, it is 3.5 billion years old. This makes it "by far the oldest known crater ever found on Earth", said Tim Johnson, one of the project leaders. Before that, a 2.2 billion-year-old crater was the oldest, the Yarrabubba crater, also located in Western Australia.

The meteorite probably hit the earth at a speed of more than 36,000 km/h. The crater it left behind was probably 100 kilometers in size.

Radiation cones indicated the impact

However, due to its age, there is not much left to see. The researchers identified it on the basis of ray cones. These are characteristic rock formations that are created during a meteorite impact. Enormous pressures are required for them to form. Their exact origin has not yet been clarified.

Meteorite impacts were frequent in the early days of the solar system. There are many craters on the moon. On Earth, they have been little known until now, which is why geologists have largely ignored them, according to Johnson.

This could now change, he said: "This study provides an important piece of the puzzle of Earth's impact history and suggests that there may be many more ancient craters that could be discovered over time."

Did meteorites contribute to the evolution of life?

The meteorite impacts could also have made an important contribution to Earth's history, said Chris Kirkland, co-author of the study, which was published in the journal Nature Communications. For example, the meteorites could have left behind basins of hot water, which could have been a favorable environment for microbial life.

"It could also fundamentally change our understanding of the formation of the crust: The immense energy of this impact could have played a role in shaping the crust of the young Earths, pushing one part of the crust under another or forcing magma from the depths of the mantle to the surface."

(wpl)