[Rockhounds] Astronomers: A comet fragment, not an asteroid, killed off the dinosaurs

[Tim Fisher]

Sure we know exactly how many just watch The Expanse. Hollywood is always
right :D

Tim Fisher
Http://OreRockOn.com 
Email nospam at orerockon.com

-----Original Message-----
From: Rockhounds [mailto:rockhounds-bounces at rockhounds.drizzle.com] On
Behalf Of J Bryan Kramer
Sent: Monday, February 22, 2021 10:33 AM
To: Rockhounds at drizzle.com: A mailing list for rock and gem collectors
Subject: Re: [Rockhounds] Astronomers: A comet fragment, not an asteroid,
killed off the dinosaurs

All based on statistical guesses not actual proof. I wish these people would
put some uncertainty in their announcements. We don't have any idea of how
many ice balls aka comets exist in the Kuiper belt do we?

BK

““There exists a law…inborn of our hearts…by natural intuition. … If our
lives are endangered by plots or violence or armed robbers or enemies, any
and every method of protecting ourselves is morally right.””
Cicero

J Bryan Krämer       North Florida, USA
photos at: http://pbase.com/photoburner


On Mon, Feb 22, 2021 at 1:22 PM Tim Fisher <nospam at orerockon.com> wrote:

> I saw this theory on some science TV show or another, it was probably 
> a way-out-there proposition back then. Good to see someone backed it 
> up :)
>
> Tim Fisher
> Http://OreRockOn.com
> Email nospam at orerockon.com
>
> -----Original Message-----
> From: Rockhounds [mailto:rockhounds-bounces at rockhounds.drizzle.com] On 
> Behalf Of Kreigh Tomaszewski
> Sent: Monday, February 15, 2021 5:50 PM
> To: Rockhounds at drizzle.com: A mailing list for rock and gem collectors
> Subject: [Rockhounds] 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.
> Some 66 million years ago, a catastrophic event occurred that wiped 
> out three-quarters of all plant and animal species on Earth, most 
> notably taking down the dinosaurs. An errant asteroid from the 
> asteroid belt <https://en.wikipedia.org/wiki/Asteroid_belt> has been 
> deemed the most likely culprit. However, in a new paper 
> <https://www.nature.com/articles/s41598-021-82320-2> published in 
> Scientific Reports, Harvard astronomers offer an alternative: a 
> special kind of comet— originating from a field of debris at the edge 
> of our solar system known as the Oort cloud <http://their
> %20findings%20also%20offer%20evidence%20that%20the%20unusual%20
>
> composition%20of%20the%20chicxulub%20impactor%E2%80%94carbonaceous%20c
> hondri
>
> te%E2%80%94indicates%20it%20originated%20from%20the%20oort%20cloud%2C%
> 20and%
>
> 20not%20from%20the%20main%20asteroid%20belt%2C%20as%20suggested%20by%2
> 0one%2
>
> 0of%20the%20more%20popular%20origin%20theories.%20it%27s%20a%20rare%20
> compos
>
> ition%20for%20main-belt%20asteroids%2C%20but%20common%20among%20long-p
> eriod%
>
> 20comets.%20the%20authors%20also%20point%20to%20other%20impact%20crate
> rs%20w
>
> ith%20similar%20composition%2C%20most%20notably%20the%20vredefort%20cr
> ater%2
>
> 0in%20south%20africa%E2%80%94the%20result%20of%20an%20impact%20some%20
> 2%20bi
>
> llion%20years%20ago%E2%80%94and%20the%20zhamanshin%20crater%20in%20kaz
> akstan
>
> %2C%20from%20an%20impact%20within%20the%20last%20million%20years.%20th
> ose%20
>
> times%20frames%20are%20in%20line%20with%20siraj%20and%20loeb%27s%20cal
> culati
>
> ons%2C%20which%20indicate%20such%20objects%20should%20strike%20earth%2
> 0once% 20every%20250%2C000%20to%20730%2C000%20years./>—that
> was thrown off course by Jupiter's gravity toward the Sun. The Sun's 
> powerful tidal forces then ripped pieces off the comet, and one of the 
> larger fragments of this "cometary shrapnel" eventually collided with 
> Earth.
>
> https://arstechnica.com/science/2021/02/astronomers-a-comet-fragment-n
> ot-an-
> asteroid-killed-off-the-dinosaurs/
> <https://arstechnica.com/science/2021/02/astronomers-a-comet-fragment-
> not-an-asteroid-killed-off-the-dinosaurs/>
> _______________________________________________
> Rockhounds mailing list
> Subscription Services:
>
> http://rockhounds.drizzle.com/mailman/listinfo/rockhounds_rockhounds.d
> rizzle
> .com
> <http://rockhounds.drizzle.com/mailman/listinfo/rockhounds_rockhounds.
> drizzle.com>
> List Usage Policy:
> http://Tomaszewski.net/Kreigh/Rockhounds/Rockhounds.shtml
> _______________________________________________
> Rockhounds mailing list
> Subscription Services:
> http://rockhounds.drizzle.com/mailman/listinfo/rockhounds_rockhounds.d
> rizzle.com
> List Usage Policy:
> http://Tomaszewski.net/Kreigh/Rockhounds/Rockhounds.shtml
>
_______________________________________________
Rockhounds mailing list
Subscription Services:
http://rockhounds.drizzle.com/mailman/listinfo/rockhounds_rockhounds.drizzle
.com
List Usage Policy: http://Tomaszewski.net/Kreigh/Rockhounds/Rockhounds.shtml