Nadir crater

The paper announcing the discovery of the feature was published in Science Advances in 2022,[1] with an impact origin being confirmed in 2024.

The crater is around 9.2 km (5.7 mi) in diameter, and formed around 66 million years ago, close to the Cretaceous–Paleogene boundary when a small asteroid struck the ocean floor.

[1] Numerical simulations of crater formation suggested a sea impact at the depth of around 800 m (1⁄2 mi) of a ≥400-m asteroid.

[1] It would have produced a fireball with a radius of >5 km (3 mi),[1] instant vaporization of water and sediment near the seabed,[1] tsunami waves up to 1 km high around the crater[3] and substantial amounts of greenhouse gases released from shallow buried black shale deposits.

[1] In 2024, detailed seismic data analysis (specifically, from reflection seismology) confirmed the impact origin of the structure beyond reasonable doubt.