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The Hazard of Near-Earth Asteroid Impacts on Earth
Frontiers ^ | 4 March 2004 | Clark R. Chapman

Posted on 12/02/2004 10:51:16 AM PST by SunkenCiv

The actual damage that a NEA impact might cause on Earth was concretely described by Baldwin, a leading advocate for the impact origin of lunar craters. Later, Opik... proposed that NEA impacts might account for mass extinctions in the Earth's paleontological record. Around the same time, Shoemaker firmly established the impact origin of Meteor Crater in Arizona... [I]t was not only a cultural but a scientific shock when Mariner 4's first photographs of the Martian surface revealed it to be covered by craters; a decade later, Mariner 10 found the same on Mercury... In 1979 and 1980, the Voyagers first encountered Jupiter and Saturn, demonstrating that cratered surfaces extended from Mercury at least out through the giant planets' satellite systems... Even after discovery of the Chicxulub impact structure in Mexico and its temporal simultaneity with the Cretaceous –Tertiary (K– T) boundary and mass extinctions, it has taken some earth scientists a while to recognize and accept the statistical inevitability that Earth is struck by asteroids and comets. Each impact, occurring on timescales of tens to hundreds of Myr, liberates tens of millions to billions of megatons (Mt, TNT-equivalent) of energy into the fragile ecosphere, which must have had dramatic consequences every time. A few researchers still consider the Chicxulub impact to be only one of several contributing factors to the K– T extinctions... Some geoscientists still think of asteroid impacts as ad hoc explanations for paleontological changes and they resist the logic that earlier, even greater impact catastrophes surely occurred. If the great mass extinctions are not attributed to impacts (e. g., explained instead by episodes of volcanism or sea regressions), one must ask how the huge impacts that must have occurred failed to leave dramatic evidence in the fossil record.

(Excerpt) Read more at boulder.swri.edu ...


TOPICS: Astronomy; History; Science; Travel; UFO's
KEYWORDS: archaeology; asteroid; catastrophism; ggg; godsgravesglyphs; history

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1 posted on 12/02/2004 10:51:16 AM PST by SunkenCiv
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To: blam; FairOpinion; farmfriend; StayAt HomeMother; Ernest_at_the_Beach
A catastrophism ping, but just to the GGG managers.
Please FREEPMAIL me if you want on, off, or alter the "Gods, Graves, Glyphs" PING list --
Archaeology/Anthropology/Ancient Cultures/Artifacts/Antiquities, etc.
The GGG Digest
-- Gods, Graves, Glyphs (alpha order)

2 posted on 12/02/2004 10:51:59 AM PST by SunkenCiv ("All I have seen teaches me trust the Creator for all I have not seen." -- Emerson)
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To: vannrox
If the great mass extinctions are not attributed to impacts (e. g., explained instead by episodes of volcanism or sea regressions), one must ask how the huge impacts that must have occurred failed to leave dramatic evidence in the fossil record.
I love that particular point. The only answer that satisfies all the available data is, "delusional belief system". :') If experience is any guide, the delusional parade is going to begin, and I won't have to save my spot along the route for very long. :')

3 posted on 12/02/2004 10:55:13 AM PST by SunkenCiv ("All I have seen teaches me trust the Creator for all I have not seen." -- Emerson)
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To: SunkenCiv

It's a small point but isn't a "near Earth impact" actually a "miss" ? And wouldn't the impact from a miss be zero?


4 posted on 12/02/2004 10:56:17 AM PST by mgc1122
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To: mgc1122

Heh... good point... but he refers to impacts by Near-Earth objects.


5 posted on 12/02/2004 10:57:51 AM PST by SunkenCiv ("All I have seen teaches me trust the Creator for all I have not seen." -- Emerson)
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To: mgc1122

I read a REALLY BAD sci fi novel about a near impact once. In the novel an asteroid or comet passed close over the north pole. Some strange gravatational effect caused a large part of our atmosphere to be draw up over the north pole in some kind of freak super high pressure system.

Long story short. The atmosphere suddenly snapped back causing thousand+ MPH winds across the planet wiping out mankind.


6 posted on 12/02/2004 11:11:40 AM PST by cripplecreek (I come swinging the olive branch of peace.)
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To: SunkenCiv
Did Asteroids And Comets Change The Tides Of Civilisation?
7 posted on 12/02/2004 11:16:48 AM PST by blam
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To: blam
Recommended reading:

And because of the cool cover:

8 posted on 12/02/2004 11:41:06 AM PST by BenLurkin (Big government is still a big problem.)
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To: SunkenCiv
I agree.
The National Education Association sucks!
9 posted on 12/02/2004 12:34:05 PM PST by Publius6961 (The most abundant things in the universe are hydrogen and stupidity.)
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To: cripplecreek
Long story short. The atmosphere suddenly snapped back causing thousand+ MPH winds across the planet wiping out mankind.

You think that's bad?
Some yoyo wrote (and sold) a novel where there is a massive nuclear explosion near Antarctica, and the resulting radioactive water races over the world's oceans at 700 miles per hour...

10 posted on 12/02/2004 12:37:38 PM PST by Publius6961 (The most abundant things in the universe are hydrogen and stupidity.)
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To: Publius6961

Yeah I think some sci fi writers are the same people coming up with conspiracy theories for the democrats. A good sci fi writer uses good hard science or at least good theoretical science.


11 posted on 12/02/2004 12:46:30 PM PST by cripplecreek (I come swinging the olive branch of peace.)
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To: BenLurkin
Velikovsky was a kook of the first water. I read it as a teenager and laughed all the way through. Isaac Asimov demolished him, once and for good, in a brilliant piece called "Worlds in Confusion."

The most risible section of Velikovsky's book was where he admitted his ideas to be incompatible with Newtonian physics: and then recommended that Newtonian physics be reconstructed so as to conform to his theories!

--Boris

12 posted on 12/02/2004 12:59:52 PM PST by boris (The deadliest weapon of mass destruction in history is a Leftist with a word processor)
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To: boris

You mean Venus didn't really get ejected from the Great Red Spot on Jupiter?


13 posted on 12/02/2004 1:35:41 PM PST by BenLurkin (Big government is still a big problem.)
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To: BenLurkin

:')


14 posted on 12/02/2004 9:50:38 PM PST by SunkenCiv ("All I have seen teaches me trust the Creator for all I have not seen." -- Emerson)
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To: cripplecreek
The atmosphere suddenly snapped back causing thousand+ MPH winds across the planet wiping out mankind.

Sounds like the UN general assembly on a typical day ...

15 posted on 12/03/2004 6:18:16 AM PST by mgc1122
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The Day the World Burned
by David A. Kring
and Daniel D. Durda
Scientific American
November 27, 2003
The cataclysm went far beyond the regular insults from which living things must recover. The asteroid or comet flashed through the sky more than 40 times as fast as the speed of sound. It was so large that when its leading edge made contact with ground, its trailing edge was at least as high as the cruising altitude of a commercial airliner. It produced an explosion equivalent to 100 trillion tons of TNT, a greater release of energy than any event on our planet in the 65 million years since then... The crater, called Chicxulub after modern Maya villages in the area, is approximately 180 kilometers in diameter and is surrounded by a circular fault 240 kilometers across, apparently produced when the crust reverberated with the shock of the impact...
The Chicxulub impact event caused the dinos to go extinct.

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16 posted on 12/11/2004 9:02:48 PM PST by SunkenCiv ("All I have seen teaches me trust the Creator for all I have not seen." -- Emerson)
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BTTT

17 posted on 01/09/2005 9:07:48 AM PST by SunkenCiv (the US population in the year 2100 will exceed a billion, perhaps even three billion.)
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bttt
18 posted on 01/31/2005 11:24:54 PM PST by SunkenCiv (Ted "Kids, I Sunk the Honey" Kennedy is just a drunk who's never held a job (or had to).)
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Catastrophism

19 posted on 03/26/2006 8:16:58 PM PST by SunkenCiv (Yes indeed, Civ updated his profile and links pages again, on Monday, March 6, 2006.)
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both of these are pretty small asteroids:

2006 JY26
1 in 185 chance
http://neo.jpl.nasa.gov/risk/2006jy26.html

2000 SG344
1 in 556 chance of Earth impact
http://neo.jpl.nasa.gov/risk/2000sg344.html


20 posted on 08/04/2006 8:36:33 PM PDT by SunkenCiv (updated my FR profile on Thursday, July 27, 2006. https://secure.freerepublic.com/donate/)
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old topic, updating standard ping message. Found while looking for Clark Chapman refs on FR.
 
Catastrophism
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21 posted on 04/29/2007 9:14:05 AM PDT by SunkenCiv (I last updated my profile on Saturday, April 28, 2007. https://secure.freerepublic.com/donate/)
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Catastrophism
 
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22 posted on 04/04/2011 6:33:43 PM PDT by SunkenCiv (Thanks Cincinna for this link -- http://www.friendsofitamar.org)
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