Scientists have identified Earth's oldest-known impact crater, and in doing so may have solved a mystery about how our planet emerged from one of its most dire periods.
Researchers have determined that the 45-mile-wide (70-km-wide) Yarrabubba crater in Australia formed when an asteroid struck Earth just over 2.2 billion years ago.
"Looking at our planet from space, it would have looked very different," said isotope geology professor Chris Kirkland of Curtin University in Australia, one of the researchers in the study published in the journal Nature Communications.