While it is known that the devastating impact of something huge that crashed into Earth 66 million years ago led to the extinction of dinosaurs, clarity on whether it was a comet or asteroid strike and where it originated was lacking.
Clearing the confusion, a new theory suggests that long-period comets originating from the Oort cloud, an icy sphere of debris at the edge of the solar system, could be behind the crash.
"Our paper provides a basis for explaining the occurrence of this event," said Avi Loeb from Harvard University.
The Chicxulub impactor, as it is known, left behind a crater off the coast of Mexico that spans 93 miles and runs 12 miles deep.
Its devastating impact brought the reign of the dinosaurs to an abrupt and calamitous end by triggering their sudden mass extinction, along with the end of almost three-quarters of the plant and animal species living on Earth.