Roughly 66 million years ago, a massive asteroid struck the modern-day Yucatán Peninsula in Mexico, triggering global wildfires, colossal tsunamis, volcanic eruptions, and a debris cloud that blocked sunlight to wipe out the dinosaurs. According to recent research published in the journal Science Advances, and reported by Science Alert, that catastrophic impactor was an extremely rare carbonaceous meteorite originating from the outer edges of the Solar System, deepening scientific understanding of a remarkably unlucky planetary collision.
Tracing the Rare Meteorite Origin to the Solar System’s Edge
While scientists already knew the impactor was a carbonaceous chondrite—a class making up less than five percent of all meteorites landing on Earth—the new study reveals it belonged to the Ornans-type carbonaceous (CO) subgroup. These represent a minuscule fraction of that already rare group. According to researchers, Jupiter typically acts as a gravitational gatekeeper blocking outer Solar System rocks, making the passage of this 10-kilometer-wide object an exceptionally improbable event.
Nickel Isotope Analysis at the Cretaceous-Paleogene Boundary
To trace the origin of the impactor, researchers analyzed geological samples from the Cretaceous-Paleogene (K-Pg) boundary layer across five distinct sites: one in Spain, one in Denmark, and three in Italy. According to the study, these samples were matched against 11 different carbonaceous chondrite meteorites from various subgroups by examining nickel isotopes. Nickel appears in much higher concentrations in primitive meteorites than in Earth’s crust, with distinct isotopic signatures pointing directly to the CO group.
Reassessing Atmospheric Sulfur and Impact Dynamics
Pinpointing the exact meteorite type alters previous assumptions about the post-impact environment. According to researchers, sulfur was previously blamed as the primary driver of the apocalyptical conditions, vaporizing into the atmosphere to block the Sun and generate acid rain that polluted soil and water for thousands of years. However, scientists note that CO meteorites contain significantly fewer volatile elements—such as carbon, zinc, water, and particularly sulfur—than other meteorite classes.
Did you know? While sulfur remains part of the extinction puzzle, researchers emphasize that fine debris ejected back into the atmosphere played the primary role in cooling the planet and collapsing food chains, rather than impact-generated sulfur alone.
Frequently Asked Questions
What type of asteroid killed the dinosaurs?
According to the Science Advances study, the impactor was an Ornans-type carbonaceous (CO) chondrite, an extremely rare meteorite type from the outer edges of the Solar System.
Where were the impact samples collected for analysis?
Researchers analyzed geological samples from the Cretaceous-Paleogene boundary taken from five European locations: one in Denmark, one in Spain, and three in Italy.
Did sulfur cause the dinosaur extinction?
While vaporized sulfur contributed to acid rain and blocked sunlight, scientists state that the impactor’s CO classification means it carried far less sulfur than other meteorite classes, pointing to fine atmospheric debris as the primary cooling factor.
Want to stay updated on the latest planetary science discoveries and asteroid tracking research? Leave a comment below or share this article to join the discussion.