A new study leads to a deeper understanding of the origin of the asteroid that wiped out the dinosaurs
A new international study led by the University of Cologne has revealed the origin of the asteroid that wiped out the dinosaurs and changed our planet's climate forever.
Geoscientists from the University of Cologne led an international study to reveal the origin of the asteroid that hit Earth 66 million years ago and permanently altered the climate of the planet. The team analysed rock samples from the boundary between the Cretaceous and Paleogene periods, which also saw the last major mass extinction event, wiping out 70% of all animal species. The results have been published in the journal Science and suggest that the asteroid would have formed outside of Jupiter’s orbit during the early development stages of our solar system.
Asteroid impact
One theory is that the mass extinction at the Cretaceous-Paleogene boundary was triggered by the impact of an asteroid, which was 10km in diameter, near Chicxulub on the Yucatán Peninsula in Mexico. Upon impact, the asteroid and huge quantities of rock vaporised. Fine dust particles would then have spread into the air and blocked out the sun, leading to dramatic changes in the living conditions for animals and plants on the planet and bringing photosynthesis activity to a standstill for several years.
The dust particles that were released from the impact would have formed a layer of sediment around the entire planet Earth. This means that the Cretaceous-Paleogene boundary can be identified and sampled in multiple places around the world. This layer has high concentrations of platinum-group metals, which would have come from the asteroid, and are extremely rare, also being found in the rocks that form the Earth’s crust.
The researchers analysed the isotopic composition of the platinum metal ruthenium at the University of Cologne’s Institute of Geology and Mineralogy, and they discovered that the asteroid would have originally come from the outer solar system.
“The asteroid’s composition is consistent with that of carbonaceous asteroids that formed outside of Jupiter’s orbit during the formation of the solar system,” said Dr Mario Fischer-Gödde, an author of the paper.
Asteroid origins
The ruthenium isotope compositions were also analysed for other impact and crater sites of different ages located on Earth for comparison. The data shows that during the last 500 million years, almost exclusively, fragments of S-type asteroids have crashed down to Earth. In contrast to the impact at the Cretaceous-Paleogene boundary, these fragments originate from the inner solar system. Over 80% of all asteroid fragments that have hit the Earth in the form of meteorites come from the inner solar system.
Professor Dr Carsten Münker, a co-author of the paper said: “We found that the impact of an asteroid like the one at Chicxulub is a very rare and unique event in geological time. The fate of the dinosaurs and many other species was sealed by this projectile from the outer reaches of the solar system.”
Source of the news:
Fischer-Gödde, M., Tusch, J., Goderis, S., Alessandro Bragagni, Mohr-Westheide, T., Nils Messling, Elfers, B.-M., Schmitz, B., Reimold, W.U., Maier, W.D., Claeys, P., Koeberl, C., Tissot, H., Bizzarro, M. and Carsten Münker (2024). Ruthenium isotopes show the Chicxulub impactor was a carbonaceous-type asteroid. Science, 385(6710), pp.752–756. doi: https://doi.org/10.1126/science.adk4868