A new study published in the journal ‘Science’ this Thursday (15) reveals that the celestial object responsible for the extinction of most dinosaurs 66 million years ago was an asteroid, not a comet, as previously suggested. According to the research, the asteroid originated from a distant area of the Solar System, located beyond Jupiter’s orbit.
The study was conducted by a team of European researchers led by Mario Fischer-Gödde, of the University of Cologne, who analyzed the sedimentary layer produced by the impact that formed the Chicxulub crater, in the current Gulf of Mexico.
This analysis was compared to other cosmic impact remnants similar to those that have occurred on Earth since its formation, approximately 3.5 billion years ago. The asteroid’s fall, which had a diameter of about 10 kilometers, triggered a series of catastrophic events, including global fires, years of darkness, and the creation of the massive crater.
In addition, the impact left a fine layer of asteroid fragments scattered around the planet, rich in platinum group elements (PGE), such as iridium, ruthenium, and palladium. These elements are rare in the Earth’s crust, indicating the asteroid’s extraterrestrial origin.
However, some scientists suggested that these chemical elements could have been deposited by massive volcanic eruptions that occurred at the same time, in the region that is now India. To clarify this doubt, Fischer-Gödde and his team focused their analyses on the isotopes of ruthenium, which vary depending on the type of meteorite.
The research showed that most large objects that hit the Earth in the past were silicate asteroids, formed in the same region of the Solar System as rocky planets, such as Earth and Mars.
However, the meteorite that caused the impact in Chicxulub was a carbonaceous asteroid, originating from a more distant region, beyond Jupiter. This rare event resulted in the collision that extinguished the dinosaurs during the Mesozoic Era.
It is estimated that more than 60% of animal and plant species were exterminated after the impact, including non-avian dinosaurs, large marine reptiles, pterosaurs, and various other forms of life. The mass extinction opened the way for the diversification of mammals, including the ancestors of humans, which began to occupy new ecological niches.
