Researchers Find Evidence of a Mysterious Giant Asteroid Impact, but They Don’t Know Where Its Crater Is

Special shards of glass, known as “tektites,” were hiding in plain sight in a museum collection

September 26, 2025

The newly identified tektites next to a two-cent euro coin — The newly identified tektites. Earth and Planetary Science Letters

Researchers have found evidence of a previously unknown asteroid impact, but the crater is still at large.

The clues of this bygone cataclysm consist of tektites—a type of natural glass that forms when Earth is struck by a meteorite. Tektites are flung into large “strewn fields” far away from their source crater.

In a study published in late August in the journal Earth and Planetary Science Letters, researchers describe newly identified tektites that have been hiding in plain sight in a collection at the South Australian Museum in Adelaide. While the other tektites in the collection, called Australasian tektites, were created around 780,000 years ago, these have an unusual chemistry and date back to around 11 million years ago, suggesting a previously unknown impact event.

“These glasses are unique to Australia and have recorded an ancient impact event we did not even know about,” Fred Jourdan, a geochronologist and geochemist from Curtin University, says in a statement. “Although the impact must have been immense, scientists are yet to locate the crater. Understanding when and how often large asteroids have struck Earth also helps us assess the risk of future impacts, which is important for planetary defense.”

The researchers suggest calling these new tektites “ananguites.” Since “australite” was already taken, they opted for a name that honors local aboriginal communities—anangu means “human being” for the Pitjantjatjara and Yankunytjatjara people.

“Based on their morphology, chemical homogeneity, low water content, presence of lechatelierite, extraterrestrial contamination (Ni, Co, Cr), geochemical and isotopic composition, and distinct age from Australasian tektites, HNa/K tektites can be defined as a new tektite group, which we propose to name ananguites,” the researchers explain in the paper.

All that’s left to do is find the associated crater. In this spirit, Jourdan and his colleagues pinpointed areas with rocks similar to but older than the ananguites, according to the New York Times’ Katherine Kornei. Because the ananguites’ chemistry suggests that the rock they were formed from originated deep inside Earth, the team also focused on volcanically active areas, per the New York Times.

“The active arcs surrounding Australia are the most likely sources, with best-matching isotopic and trace element signatures from the Philippines (Luzon), Indonesia (Sulawesi) and Papua New Guinea (Bismarck),” they explain in the paper—though other places can’t be ruled out.

Steven Jaret, a planetary geologist at the American Museum of Natural History who did not participate in the study, tells the New York Times that this approach was “very reasonable.” But finding a specific circular structure among many other circular structures is going to be difficult, Aix-Marseille University geophysicist and study co-author Pierre Rochette tells the outlet.

What’s more, the crater may no longer be visible, he adds.

Even if researchers never track down the 11-million-year-old crater, the study still stands as a reminder that, as humanity starts to reach across the solar system and into the rest of the universe, we still know very little about the history of our own planet.

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