Australia’s Ancient Impact: A Crater Older Than Time
Earth’s early history is written in rocks, and Western Australia now claims a headline as old as the planet itself. Researchers from Curtin University have proposed that a fossilised meteorite crater in the Pilbara region—deep in the archipelago of ancient crust around North Pole Dome and Marble Bar—dates back about 3.5 billion years. If confirmed, it would be the oldest known meteorite impact crater on Earth, pushing back the record by hundreds of millions of years and prompting a major rethink of early planetary dynamics.
Where and how the discovery was made
The fieldwork focused on North Pole Dome, about 40 kilometres west of Marble Bar. This area houses some of the oldest preserved crust on Earth, offering a window into a tumultuous adolescence for our planet. The research team looked for telltale hallmarks of a massive impact—shock textures and microscopic patterns forged under extreme heat and pressure.
In rocks scanned and sampled at the site, the scientists found shatter cones—conical rock formations that form only under the intense pressures of a meteorite strike. These features, alongside other shock indicators, pointed to a colossal event that shaped the landscape long before plate tectonics as we know them today.
According to lead researchers, the evidence suggests a meteorite impact mélange travelling at speeds around 36,000 kilometres per hour could have carved a crater exceeding 100 kilometres in diameter. The scale of disruption implied by such a strike has implications beyond a single crater, hinting at global consequences for the early Earth’s crust and atmosphere.
What makes this crater so old—and why it matters
Traditionally, the oldest widely accepted impact crater was thought to be about 2.2 billion years old. The Pilbara claim pushes that boundary back by more than a couple of billion years, potentially rewriting chapters on how early Earth evolved, how its atmosphere formed, and how early life might have first faced an unstable, bombarded surface.
The discovery is not just about “how old” a feature is; it challenges timelines for when the Earth cooled enough to host stable oceans, sustain an atmosphere, and allow for primitive life to emerge. An impact this ancient could have left lasting scars on early planetary evolution, influencing crust formation, mineral distribution, and the timing of tectonic processes elsewhere in the system that would eventually give rise to continents as we know them.
Competing science and a fallible path to certainty
In science, a single study rarely settles a matter of planetary history. In July 2025, Harvard researchers offered a different interpretation: their fieldwork suggested the same site—or a nearby one—might be younger and smaller. They estimated a strike around 2.7 billion years ago and a crater roughly 16 kilometres wide. This divergence highlights how geology relies on evolving methods, cross-checking evidence, and sometimes reinterpreting data as new analyses emerge.
Two different conclusions do not spell failure; they demonstrate the scientific method in action. Question, test, debate, and refine. The Pilbara finding invites further drilling, dating, and comparative studies across similar ancient terrains to converge on a clearer picture of Earth’s dawn of impact.
The bigger picture: why this matters for Earth’s story
Whether the oldest known crater is 3.5 billion years old or somewhat younger, the core message remains: our planet has been shaped by cosmic violence since very early times. Each new discovery informs our understanding of early life, atmospheric evolution, and the rough-and-tumble process of early crust formation. The record is incomplete, but it is growing, one field excursion at a time.
Conclusion: science in motion
Chicxulub in Mexico famously marks the dinosaur extinction, but the Pilbara’s ancient rocks remind us that Earth’s history is a global, multi-threaded narrative. As researchers debate how old the oldest meteorite crater truly is, they bring us closer to answering the big questions: when did life begin, how did the atmosphere form, and why is our planet uniquely equipped for habitability?
