An ancient asteroid impact in Australia is revealed in a new study from Curtin University, which identifies shards of glass created when the giant space rock collided with the Earth, providing clues to a previously unknown event.
Tekites are a type of natural glass produced in such events as the energy released during the impact event melts material on the planet's surface. The kinetic power of these asteroid impacts can fling the shards for hundreds or thousands of kilometers, yet the new tekites first discovered in this latest study have only been found in a limited area of Australia.
"These glasses are unique to Australia and have recorded an ancient impact event we did not even know about," said co-author Professor Fred Jourdan of Curtin's School of Earth and Planetary Sciences.
Whenever a new tekite is discovered, it opens a fresh chapter of Earth's mysterious past for scientists to discover. Searching for clues in the surroundings and the tekites themselves offers up puzzle pieces to locate previously unknown impact sites, filling in parts of Earth's ancient past.
"They formed when an asteroid slammed into Earth, melting surface rock and scattering debris for thousands of kilometres," Jourdan added. "These tiny pieces of glass are like little time capsules from deep in our planet's history."
"What makes the discovery even more intriguing is that, although the impact must have been immense, scientists are yet to locate the crater," Jourdan said.
Five previous tekite fields have been discovered in Central Europe, North America, the Ivory Coast, Central America, and one spread between China and Australia. Each of these represents a separate impact site and contains its own unique variety of tekite.
The impact's discovery was made as a result of analyzing the specific type of tekite in question. Researchers studied known tekite samples from museum collections, subjecting the pieces to magnetic susceptibility measurements in the search for any outliers. In doing so, the team identified a previously unknown tektite sourced from a single region in Australia, suggesting a previously known ancient impact. Despite knowing the general area to look, no direct impact site has been found, possibly due to the event's remote age, which has allowed for significant geological changes in the intervening years.
"These tektites are unique because of their unusual chemistry and their age, which is about 11 million years," lead author Anna Musolino, a PhD student at Aix-Marseille University, said.
The immediate comparison was to another famous tektite-producing event, which resulted in the Australasian tektite-strewn field. Differences between the two are stark. The Australasian tekites are spread over an enormous radius, covering half the globe, while the new tekites are much more tightly concentrated, currently limited to South Australia.
Additionally, the Australasian examples were dated to roughly 780,000 years ago, while the new tekites are significantly older. From this evidence, which displays a substantial deviation from known tektites, researchers are sure that their findings represent a previously unrecognized impact event in Earth's past. With new tools such as NASA's DART allowing humans to deflect dangerous asteroids for the first time, a better understanding of how such events have caused ancient destruction is essential to a safer future.
"Understanding when and how often large asteroids have struck Earth also helps us assess the risk of future impacts, which is important for planetary defence," Jourdan concluded.
The paper, "A New Tektite Strewn Field in Australia Ejected from a Volcanic Arc Impact Crater 11 Myr Ago," appeared in Earth and Planetary Science Letters on August 29, 2025.