A new study has provided new insights into the asteroid that hit Earth 66 million years ago, causing a mass extinction that led to the end of the dinosaurs. Scientists have now identified the impactor as a carbon-rich “C-type” asteroid, a type of space rock that likely originated in the asteroid belt between Mars and Jupiter. By studying ruthenium isotopes found in the global debris layer left by the impact at the Chicxulub impact crater, scientists have determined that the asteroid’s composition is different from natural materials on Earth. Understanding the asteroid’s components is also expected to help scientists learn more about similar future asteroid impacts.
Ruthenium analysis indicates asteroid origin
The research team, including Mario Fischer-Gödde from the University of Cologne, focused in particular on ruthenium because of its rarity in the Earth’s crust, which makes it an excellent marker for extraterrestrial material. Analyzing samples from locations in Denmark, Italy, and Spain, the team found a consistent isotopic composition that matches that of carbonaceous asteroids.
This discovery is significant because it dispels other theories that suggested the impactor could have been a comet or that volcanic eruptions like those in the Deccan Traps were responsible for the presence of rare metals like ruthenium in the debris layer. The uniformity of the isotopic composition across geographic locations strengthens the case for an extraterrestrial origin for the asteroid.
Asteroid Belt or Oort Cloud: Possible Source
The study suggests the asteroid likely came from the asteroid belt between Mars and Jupiter. A collision between two asteroids in that belt could have sent the fragment on a trajectory that ultimately led to a collision with Earth.
However, the possibility that the asteroid came from the more distant Oort Cloud, a region surrounding the Solar System, has not been completely ruled out. This uncertainty leaves room for further exploration and research to better understand the origins of such catastrophic events.
Impact on our understanding of Earth’s history
Dr Craig Walton, from the University of Cambridge, who was not directly involved in the study, told The Guardian about the importance of the research in deepening our understanding of Earth’s history. While there are still unanswered questions about the exact origins of the asteroid, the study provides key insights into the nature of celestial objects that have played a dramatic role in shaping the planet’s evolutionary path.
These discoveries contribute to a better understanding of how such events influenced the development of life on Earth, offering new perspectives on our planet’s vulnerability to cosmic impacts.