Strange glassy blobs scattered across the Australian desert are the remnants of a long-forgotten meteorite impact. Recent research led by geoscientist Anna Musolino of Aix-Marseille University reveals that these unique glass spheres, dubbed “ananguites,” formed during a massive impact around 11 million years ago.
What’s intriguing is that scientists have yet to locate the crater from such a powerful event. Impact sites typically leave behind clear evidence, yet this one remains elusive. Fred Jourdan, a geochronologist at Curtin University, describes the ananguites as “time capsules” from our planet’s history. They formed when an asteroid crashed into Earth, melting rock and scattering debris for miles.
Australia is already known for its tektites, which are tiny glass beads created by other meteorite impacts. The Australasian strewnfield contains tektites from a massive impact believed to have occurred about 788,000 years ago. The tektites found in Australia are called australites, and their abundance ties back to this more recent event.
Interestingly, a 1969 study by NASA scientists found eight australite samples that seemed different from the rest. They suggested these might be remnants of a separate impact, but the theory didn’t gain traction until Musolino and her team revisited the samples.
Using detailed descriptions from the earlier study, they identified six new ananguites in the South Australian Museum’s collection. These samples share unique features, including differing chemical compositions and magnetic properties, indicating they’re from a separate impact.
To confirm their age, the researchers used argon dating, establishing that these ananguites are indeed 11 million years old. This age tells us they originated from an older event, but the exact location of the impact remains a mystery. Intense weathering and the aridification of central Australia, which began about 33 million years ago, might explain why the crater hasn’t been found.
Just like the elusive source crater of the Australasian strewnfield tektites, this search for the ananguite’s crater has been a long-standing challenge in the field of impact science. The differences in the chemical makeup of western and eastern ananguites could help narrow down the site, but more samples will be needed for confirmation.
These discoveries not only deepen our understanding of Earth’s geological history but also highlight the mysteries that still exist within our planet. As geoscientists continue to explore, we may uncover more about impacts that shaped our world long ago.
For more in-depth information on the topic, you can refer to the research published in Earth & Planetary Science Letters here.
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