Ancient Asteroid Strike Revealed Through Tektite Analysis

Researchers have discovered evidence of an ancient asteroid strike on Earth, dating back around 11 million years, through a comprehensive analysis of tektites stored in the South Australian Museum in Adelaide. The study, published in the journal Earth and Planetary Science Letters, shed light on the origins of a previously unknown type of tektite, named Ananguites, which were found to be significantly older than initially believed. By dating and analyzing the chemical composition of these tektites, the researchers were able to map out a possible location of the asteroid impact crater, highlighting the challenges of identifying such sites in regions with extensive volcanic activity.

Key Takeaways:

• The tektites analyzed in the study, known as Ananguites, have a chemical composition distinct from the more common Australasites, which are believed to have originated from an 800,000-year-old asteroid strike.
• The Ananguites have been dated to around 10.8 million years old, making them one of the oldest known tektites.
• The team narrowed down the possible location of the asteroid impact crater by identifying areas with rocks older than Ananguites and matching their elemental composition.
• The researchers suggest that the crater may be located near chains of volcanoes in the Philippines, Indonesia, or Papua New Guinea.
• The study highlights the challenges of identifying impact craters in regions with extensive volcanic activity, where circular structures may be frequent and easily confuse researchers.
• The researchers believe that more Ananguites may be hiding in plain sight in museum and private collections, and future research may lead to the discovery of additional ancient asteroid strike evidence.

Statistics:

• The team analyzed over 5,000 tektites from the South Australian Museum, retaining 417 for further analysis.
• The researchers found 6 tektites with a distinct chemical composition, which they aged-dated to 10.8 million years.
• The Ananguites were found in an area of approximately 10 percent of Earth's surface.
• The researchers believe that the asteroid strike that produced the Ananguites was around 11 million years ago.
• The study's findings may be expanded upon in future research, potentially leading to further discoveries of ancient asteroid strike evidence.

Sources:

• Musolino, A. et al. (2023). "Unveiling a new type of tektite: Ananguite." Earth and Planetary Science Letters (Volume 590, Issue 116075)
• Rochette, P. (Interviewed in the article)