A location in Western Australia that used to be named as the oldest meteorite impact crater on Earth is now actually a lot younger than that, scientists announced today in Science Advances. The structure — previously dated to 3.5 billion years ago and located within Western Australia’s North Pole Dome region of the Pilbara — was believed to be older than any of Earth’s known impact craters. Today, new research published in the journal Geochemistry found that what we now call the Miralga impact structure is, in fact, much younger, at 2.7 billion years old, and considerably smaller in diameter. This recasts earlier ideas on the early Earth’s geological activity and questions previous theories regarding impact-driven crust formation or perhaps even early life.

Miralga Crater Loses Oldest Impact Title but Gains New Scientific Relevance

As per The Conversation article republished by Space.com, the teams that explored the crater could only point to one thing that was likely — it had been formed by an impact. However, they ultimately disagreed as to whether this event had been and how large it was. Younger rocks contain shatter cones, indicating Earth’s early continental geology shielded the impact to a specific 2.7 billion-400 million-year period despite earlier assertions.

They made the determination to honour the cultural revision of one site from 100 km across to a more manageable 16 km wide crater named Miralga. It’s the site – still affected by seawater – of events too recent to influence the Earth’s crust.

The Miralga basalt feature (unique to basalt) is a rare site for an instrument to practice on before heading to Mars, while advancing our understanding of impacts and early life prospects.

Isotopic dating to clarify the crucial part played by this, the oldest crater on Earth and unique in a geological sense, in planetary science and early Earth history is presently ongoing at Miralga.