Australia's 3-Billion-Year-Old Asteroid Crater Sets Record

Deep in the Australian outback, rust-colored rocks shaped like an upside-down ice cream cone are rewriting what we know about life on Earth.

Researchers at Curtin University just confirmed these formations in Western Australia's Pilbara region contain evidence of the oldest known asteroid impact on our planet. Using tiny zircon crystals no bigger than grains of sand, they pinpointed the strike to three billion years ago.

Professor Chris Kirkland led the team that made this breakthrough discovery. "You're hunting through microscopic slices of rock to find those crystals that tell you about the various processes that have happened," he explained about the painstaking work of firing laser beams into crystals to determine their age.

The finding pushes back the record by 800 million years. Previous evidence pointed to an impact at Yarrabubba, also in the Pilbara, occurring around 2.2 billion years ago.

What makes this discovery special isn't just its age. The Earth three billion years ago looked nothing like today.

Our planet was covered almost entirely by water, with only a few volcanic islands poking above the surface. The atmosphere was thick with carbon dioxide, and the moon hung closer to Earth, creating massive tides.

Why This Inspires

This ancient impact might hold the key to understanding how life emerged on Earth. While the asteroid strike would have caused catastrophic damage at the time, creating what Professor Craig O'Neill from Queensland University of Technology called "a nuclear winter," it also may have set conditions for early life to flourish.

The Pilbara region has become a treasure trove for scientists worldwide, even attracting NASA's attention. Its ancient rocks are among the oldest and best-preserved pieces of Earth's crust, giving researchers a rare window into what scientists call "deep time."

Professor Tim Johnson, who co-authored the study, noted this is the only confirmed impact from the Archean eon, a period when asteroid strikes would have been far more common than today. While other planets like Mars and Venus still show visible craters, evidence on Earth gets erased by erosion, plate tectonics, and weather over billions of years.

Western Australia's unique geology has preserved what everywhere else has lost. "These impacts were actually hitting everywhere but we're just very lucky in West Australia to have a deep time record," Kirkland said.

The discovery opens new questions about Earth's violent early history and how those cosmic collisions shaped the emergence of life itself.