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)
Birds! It’s just like 66 million years ago, only smaller!
Thanks for another really cool post, Kate.
This piece from 2018 suggests that only ground-dwelling birds survived the “K-Pg” event, and the more diverse and abundant tree-dwelling species didn’t.
https://www.independent.co.uk/news/science/how-birds-survived-dinosaur-killing-asteroid-a8385621.html
https://www.usatoday.com/story/news/nation/2021/02/23/half-male-female-rare-cardinal-bird-photographed-erie-warren-county/4554937001/
Yes I saw that! Very unusual. It can also happen with other species: https://www.birdsoutsidemywindow.org/2017/12/31/the-letters-w-and-z/
Alas, it was “a chunk of comet” killed the beasts! (Shoutout to all you KING KONG fans.)
When I first-heard that birds are dinosaurs was a revelation. The sight of one– whether it a crow, red-tailed hawk or yes, even a pigeon!– still evokes a sense of amazement.
Another recent study, this one from UT Austin, concludes that it was an asteroid. No mention of whether they considered the comet alternative.
https://phys.org/news/2021-02-asteroid-crater-case-dinosaur-extinction.html