Astronomers: A comet fragment, not an asteroid, killed off the dinosaurs
Jupiter's gravity pushed comet toward Sun; comet was ripped apart by
tidal forces. By Jennifer Ouellette, ArsTechnica, February 15, 2021
[arstechnica.com]

The open access paper is:

Siraj, A. and Loeb, A., Breakup of a Long-Period Comet
as the Origin of the Dinosaur Extinction.
Scientific Reports volume 11, Article number: 3803 (2021)
[www.nature.com]
[www.cfa.harvard.edu]

Yours,

Paul H.

"The past is never dead. It's not even past."
William Faulkner, Act 1, Scene III, Requiem for a Nun (1951)