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

[Axel Emmermann]

More than 100.000 in the size of 100 Km ore thereabout, Bryan.
Objects ranging from tiny grains to dwarf planets such as Pluto, Haumea and Makemake make up that belt..
Actually they are called TUO's (TransUranian Objects) or KBO (Kuyper Belt Objects).

a 1.000 times further away lies the Oort Cloud.
There you'd find probably billions of comets. That cloud is sometimes perturbed by passing stars and every now and then a comet is pushed to the inner solar system. This cloud is VAST and reaches as far as somewhere between one quarter and halfway to the nearest star (Proxima Centauri). Needles to say that comets may be "underway" for several 100.000 or millions of years to swing by the sun once and return, never to be seen again.  Unless they hit something... Something that has been falling towards the sun for eons pack a mighty punch. I'd expect higher velocities than with normal KB-comets.

Cheers
Axel 

-----Oorspronkelijk bericht-----
Van: Rockhounds <rockhounds-bounces at rockhounds.drizzle.com> Namens J Bryan Kramer
Verzonden: maandag 22 februari 2021 19:33
Aan: Rockhounds at drizzle.com: A mailing list for rock and gem collectors <rockhounds at rockhounds.drizzle.com>
Onderwerp: 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
>
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>
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> 20and%
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>
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> ater%2
>
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> 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/>
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