Study: Dinosaur killer was rare asteroid from unusually far away

A new study has revealed that the asteroid responsible for the last mass extinction 66 million years ago – which wiped out the dinosaurs – originated in the farthest parts of our solar system, unlike most asteroids that have struck Earth.

Researchers in Europe and the United States have discovered that the dinosaur-killing asteroid formed outside Jupiter's orbit in a very cold region and was rich in water and carbon, according to Results The study was published Thursday in the journal Science.

Of all the cosmic bodies they studied that hit Earth in the past 500 million years, the water-rich asteroid was the only one that wiped out the dinosaurs, the researchers said. Objects that originated closer to the sun tend to be drier, said Francois Tissot, a professor at the California Institute of Technology who co-authored the study.

“All the other impacts were caused by an object that was close to the sun and encountered it here,” Tiso said. “So the object that killed the dinosaurs was really special for two reasons – in terms of what it did, and in terms of where it originated.”

This terrifying body was the one that created the Chicxulub crater in Mexico’s Yucatán Peninsula. Although researchers have not been able to study a direct sample of the asteroid since it was destroyed, Tiso explained that the dust from the impact fell to Earth, allowing them to study the tiny particles that were deposited in the layers of the Earth.

Specifically, they studied the element ruthenium, which is extremely rare on Earth and can be definitively traced back to that asteroid.

The study confirmed previous findings that identified the asteroid as a carbonaceous, or C-type, asteroid, but refuted a 2021 study. hypothesis The dinosaur killer is likely guilty.

“Comets come from very far from the Sun, but they are mostly made of ice and dust,” Tissot said. “The ruthenium content has not been measured in any comet, so we have no point of comparison, but based on other indicators from other elements that the scientific community has been able to measure over time, it seems unlikely that it is a comet.”

Tissot noted that the study was a step forward in efforts to understand the evolution of our planet.

“If we do enough studies across Earth's history, we suddenly have a record of all of Earth's evolution, and we can start asking other questions,” he added.