© 2025 Connecticut Public

FCC Public Inspection Files:
WEDH · WEDN · WEDW · WEDY
WEDW-FM · WNPR · WPKT · WRLI-FM
Public Files Contact · ATSC 3.0 FAQ
Play Live Radio
Next Up:
0:00
0:00
0:00 0:00
Available On Air Stations

Dinosaur-Killing Impact Came From Edge Of Solar System, New Theory Suggests

A skeleton of an <em>Allosaurus</em> on display at Drouot auction house in Paris in October. A new theory says the dinosaurs were killed by a comet fragment that originally came from the edge of the solar system.
Thibault Camus
/
AP
A skeleton of an Allosaurus on display at Drouot auction house in Paris in October. A new theory says the dinosaurs were killed by a comet fragment that originally came from the edge of the solar system.

For decades, the prevailing theory about the extinction of the dinosaurs was that an asteroid from the belt between Mars and Jupiter slammed into the planet, causing cataclysmic devastation that wiped out most life on the planet.

But new research out of Harvard University theorizes that the Armageddon-causing object came from much farther out than originally believed.

According to this new theory, the devastation came not from a relatively nearby asteroid, but from a sort of long-distance comet that came from the edge of the solar system in an area known as the Oort cloud.

The gravity from Jupiter pulled the comet into the solar system. At that point, according to Amir Siraj, a Harvard student who co-authored the paper with Professor Avi Loeb, "Jupiter acts as a kind of pinball machine."

The theory goes: Jupiter's gravity shot this incoming comet into an orbit that brought it very close to the sun, whose tidal forces caused the comet to break apart. Some of the comet's fragments entered Earth's orbit, and one slammed into the coast of Mexico.

So long, dinosaurs.

The theory also posits that large-impact craters, such as the so-called Chicxulub crater caused by this impact, are more likely to be made of "carbonaceous chondrite" — a primitive material dating to the beginning of the solar system. Only about 10% of asteroids in the belt are made of carbonaceous chondrite, the researchers said.

"Our hypothesis explains the composition of the largest confirmed impact crater in Earth's history as well as the largest one within the last million years," the authors wrote.

Although Siraj and Loeb's novel theory has raised eyebrows among the scientific community, it has also been criticized. "I believe their work has several intrinsic problems," Bill Bottke, a planetary scientist at the Southwest Research Institute in Boulder, Colo., told The New York Times.

For instance, Bottke says, the proposed model overestimates how frequently long-period comets actually get pulled apart by the sun. "There's still wiggle room if somebody really wants it to be a comet," he said. "I just think making that case is really hard."

Copyright 2021 NPR. To see more, visit https://www.npr.org.

Matthew S. Schwartz is a reporter with NPR's news desk. Before coming to NPR, Schwartz worked as a reporter for Washington, DC, member station WAMU, where he won the national Edward R. Murrow award for feature reporting in large market radio. Previously, Schwartz worked as a technology reporter covering the intricacies of Internet regulation. In a past life, Schwartz was a Washington telecom lawyer. He got his J.D. from Georgetown University Law Center, and his B.A. from the University of Michigan ("Go Blue!").

The independent journalism and non-commercial programming you rely on every day is in danger.

If you’re reading this, you believe in trusted journalism and in learning without paywalls. You value access to educational content kids love and enriching cultural programming.

Now all of that is at risk.

Federal funding for public media is under threat and if it goes, the impact to our communities will be devastating.

Together, we can defend it. It’s time to protect what matters.

Your voice has protected public media before. Now, it’s needed again. Learn how you can protect the news and programming you depend on.

SOMOS CONNECTICUT is an initiative from Connecticut Public, the state’s local NPR and PBS station, to elevate Latino stories and expand programming that uplifts and informs our Latino communities. Visit CTPublic.org/latino for more stories and resources. For updates, sign up for the SOMOS CONNECTICUT newsletter at ctpublic.org/newsletters.

SOMOS CONNECTICUT es una iniciativa de Connecticut Public, la emisora local de NPR y PBS del estado, que busca elevar nuestras historias latinas y expandir programación que alza y informa nuestras comunidades latinas locales. Visita CTPublic.org/latino para más reportajes y recursos. Para noticias, suscríbase a nuestro boletín informativo en ctpublic.org/newsletters.

The independent journalism and non-commercial programming you rely on every day is in danger.

If you’re reading this, you believe in trusted journalism and in learning without paywalls. You value access to educational content kids love and enriching cultural programming.

Now all of that is at risk.

Federal funding for public media is under threat and if it goes, the impact to our communities will be devastating.

Together, we can defend it. It’s time to protect what matters.

Your voice has protected public media before. Now, it’s needed again. Learn how you can protect the news and programming you depend on.

Related Content