The research shows that an asteroid caused a global winter, causing the dinosaurs to become extinct (representative).
Washington:
For decades, there has been a heated debate about the cosmic rock that wiped out the dinosaurs. But a new study has yielded important and surprising information about the origins of the impact.
Researchers, whose findings were published Thursday in the journal Science, have used an innovative technique to show that the apocalyptic culprit that slammed into Earth's surface 66 million years ago, causing the most recent mass extinction, formed beyond the orbit of Jupiter.
They also reject the idea that it was a comet.
The new insights into the suspected asteroid that hit Chicxulub, on what is now Mexico's Yucatán Peninsula, could lead to a better understanding of celestial bodies that have hit our planet.
“Now, with all this knowledge… we can say that this asteroid originally formed beyond Jupiter,” Mario Fischer-Godde, lead author of the study and a geochemist at the University of Cologne, told AFP.
The findings are remarkable, as this type of asteroid rarely hits Earth.
According to Fischer-Godde, such information could be useful in assessing future threats or determining how water got to this planet.
Examples
The new findings are based on an analysis of sediment samples formed between the Cretaceous and Paleogene periods, the time when the asteroid made its catastrophic impact.
Researchers measured isotopes of the element ruthenium, which is not uncommon on asteroids but extremely rare on Earth. So by inspecting the deposits in multiple geological layers that mark the debris from the Chicxulub impact, they could be sure that the ruthenium they studied came “100 percent from this asteroid.”
“Our laboratory in Cologne is one of the few laboratories that can perform these measurements,” Fischer-Godde said. “It was the first time that such research techniques were applied to layers of impact debris.”
Ruthenium isotopes can be used to distinguish between two main groups of asteroids: C-type or carbonaceous asteroids that formed in the outer Solar System, and S-type silicate asteroids from the inner Solar System, closer to the Sun.
The research shows that the asteroid that caused a massive earthquake, brought about a global winter and wiped out the dinosaurs and most other life forms was a type C asteroid that formed beyond Jupiter.
Research from twenty years ago also made this assumption, but with much less certainty.
The findings are striking because most meteorites (pieces of asteroids that fall to Earth) are of type S, Fischer-Godde pointed out.
Does this mean that the Chicxulub impactor formed beyond Jupiter and was headed straight for our planet? Not necessarily.
“We can't say for sure where the asteroid was hiding just before it hit Earth,” Fischer-Godde said, adding that after it formed, it may have made a stopover in the asteroid belt, which lies between Mars and Jupiter and is where most meteorites come from.
No comet
The study also rejects the idea that the devastating impact was a comet, an amalgam of icy rock from the outer reaches of the solar system. Such a hypothesis was put forward in a much-discussed 2021 study based on statistical simulations.
Sample analyses now show that the body had a very different composition than a subset of meteorites thought to have been comets in the past. It is therefore “unlikely” that the impact in question was a comet, Fischer-Godde said.
As for the broader utility of his findings, the geochemist made two suggestions.
He is convinced that a more precise description of the nature of the asteroids that have hit Earth since its formation some 4.5 billion years ago could help solve the mystery of the origin of water on our planet.
Scientists believe the water may have been brought to Earth by asteroids. These are probably type C asteroids, like the one that hit Earth 66 million years ago. However, these asteroids are less common.
By studying past asteroids, humanity can also prepare for the future, Fischer-Godde said.
“If we find that past mass extinctions could also be linked to C-type asteroid impacts, then… if a C-type asteroid ever comes into orbit around Earth, we need to be very careful,” he said, “because it could be the last one we see.”
(Except for the headline, this story has not been edited by DailyExpertNews staff and is published via a syndicated feed.)