
24 February 2021
Ever since the early 1980s when Luis and Walter Alvarez discovered that the Chicxulub Crater in the Yucatan and the extinction of the dinosaurs were caused by the same event, we’ve talked about the “asteroid” that killed the dinosaurs. Recently two Harvard researchers took a new look at the composition of Chicxulub rocks and the physics of comet behavior and revised that conclusion. It wasn’t an asteroid that killed the dinosaurs. It was a chunk of comet!
Asteroids live in the main belt of the inner solar system located between Mars and Jupiter. Comets are from the Oort cloud of interstellar space.

The video below explains how a piece of comet could break off and cause the Cretaceous–Paleogene extinction … and how soon one could hit us again. By the way, Jupiter is involved.
Yow! Oh no!

A chunk of comet killed the big dinosaurs. Fortunately we still have the little ones with us … Birds!
(screenshot at top from Harvard University video, remaining photos from Wikimedia Commons; click on the captions to see the originals)