In which of the following countries can be found the oldest known asteroid crater on Earth?

The Yarrabubba crater in Western Australia is the oldest known asteroid crater on Earth.

Estimated to have been formed over 2.229 billion years ago, the crater (which is known as an “impact structure”) came into existence when a meteor or other space debris collided with the Earth’s surface. The impact occurred during a period in Earth’s history called the Proterozoic eon.

Due to its age, the diameter of the original crater is uncertain, although estimates put it at some 40 miles (70 km) across. While the structure has eroded due to age and natural weathering, scientists were able to date it by analyzing minerals (primarily zircon and monazite) found in the crater. They then used uranium-lead dating to analyze the samples and determine how much time had passed since the impact, thus determining the age of the crater.

Prior to the discovery of the Yarrabubba crater, the world’s oldest known crater was the Vredefort crater in South Africa, which is estimated to be 2.02 billion years old.