RESEARCHERS IDENTIFY METEORITE CLASS THAT KILLED DINOSAURS

Researchers have identified the class of meteorite responsible for the extinction event 66 million years ago as a carbon monoxide chondrite, a rare type of space rock that comprises only five per cent of meteorites sampled on Earth. Scientists at the University of British Columbia analysed trace elements in samples from a clay layer created by the impact and determined that the Chicxulub asteroid, which struck the Yucatán Peninsula in Mexico, belonged to this primitive class of material. The findings were published in Science Advances. Dr Philippe Claeys, a visiting professor at the university, stated that the discovery underscores "how unlucky the dinosaurs were" to be struck by such a rare, distant projectile.

The six-mile-wide Chicxulub asteroid disintegrated upon impact, creating a major crater and scattering shards thousands of miles across the planet. The research suggests the meteorite may have originated from the outer region of the asteroid belt near Jupiter or the distant reaches of the solar system. Claeys collaborated with researchers across Europe, including colleagues at the Institut de Physique du Globe in Paris and Université de Paris. The findings reduce the likelihood that sulphur within the meteorite, an element capable of combustion, was the primary cause of the extinction event.

The research does not alter the established theory of what occurred when Chicxulub struck Earth, but it refocuses attention on atmospheric effects. Claeys noted that "the fine debris thrown into the atmosphere would have been the primary factor" in the extinction of approximately 75 per cent of living species. Other researchers have proposed alternative or complementary causes, including climate change and volcanic activity preceding the impact. Further study of the asteroid and its consequences continues.