The asteroid responsible for our last mass extinction 66 million years ago — the one that wiped out the dinosaurs — originated from the far reaches of our solar system, unlike most asteroids that hit Earth, a new study reveals.
Researchers in Europe and the United States have discovered that the dino-killing asteroid formed in a very cold region beyond Jupiter’s orbit, rich in water and carbon. Findings Published Thursday in the journal Science.
Of all the cosmic bodies that hit Earth in the last 500 million years, only a watery asteroid killed the dinosaurs, the researchers said. Objects formed closer to the Sun are much drier, said François DeSot, a professor at the California Institute of Technology who wrote the paper.
“Every other impact was met here by an object that was closer to the Sun,” DeSot said. “So what killed the dinosaurs was really special in two ways — what it did, and where it came from.”
It was this apocalyptic material that created the Chicxulub Crater in Mexico’s Yucatan Peninsula. Tissot explained that although researchers were unable to examine a live sample of the asteroid because it was destroyed, the dust from its impact fell back to Earth, allowing them to study finer particles deposited in Earth’s layers.
In particular, they studied the element ruthenium, which is extremely rare on Earth and was definitely discovered by the asteroid.
The study confirmed earlier findings that identified the asteroid as a carbonaceous-type or C-type asteroid, but refuted 2021. hypothesis The dinosaur killer could have been a comet.
“Comets come from far away from the Sun, but they’re mostly made of ice and dust,” DeSot said. “No comet has been measured for ruthenium, so we don’t have a point of comparison, but based on other indicators of other elements that the community has been able to measure over time, it’s unlikely to be a comet.”
DeSot noted that the study is a step forward in efforts to understand the evolution of our planet.
“If enough studies are done throughout Earth’s history, suddenly we have a record of all of Earth’s evolution,” he said, “and we can start asking other questions.”
