[meteorite-list] Crackpot impact theory

From: star-bits_at_comcast.net <*star-bits_at_meteoritecentral.com*> Date: Sat Sep 24 15:05:01 2005 Message-ID: <092420051904.9611.4335A35A00029FC40000258B22007610649C9B070DD39D0E9B9C_at_comcast.net> · star-bits_at_meteoritecentral.com

--
Eric Olson
ELKK Meteorites
http://www.star-bits.com
> 
> Why do you call this a "crackpot" theory?
> 
> Regards,
> Pete
> 
> From: Darren Garrison <cynapse_at_charter.net>
> Reply-To: cynapse_at_charter.net
> To: Meteorite-list_at_meteoritecentral.com
> Subject: [meteorite-list] Crackpot impact theory
> Date: Sat, 24 Sep 2005 13:35:00 -0400
> 
> http://newswire.ascribe.org/cgi-bin/behold.pl?ascribeid=20050923.103123&time=11%
> 2050%20PDT&year=2005&public=0
> 
> Fri Sep 23 11:50:07 2005 Pacific Time
> 
>        Supernova Explosion May Have Caused Mammoth Extinction
>         BERKELEY, Calif., Sept. 23 (AScribe Newswire) -- A distant supernova 
> that exploded 41,000
> years ago may have led to the extinction of the mammoth, according to 
> research that will be
> presented tomorrow (Sept. 24) by nuclear scientist Richard Firestone of the 
> U.S. Department of
> Energy's Lawrence Berkeley National Laboratory (Berkeley Lab).
> 
>         Firestone, who conducted this research with Arizona geologist Allen 
> West, will unveil this
> theory at the 2nd International Conference "The World of Elephants" in Hot 
> Springs, S.D. Their
> theory joins the list of possible culprits responsible for the demise of 
> mammoths, which last roamed
> North America roughly 13,000 years ago. Scientists have long eyed climate 
> change, disease, or
> intensive hunting by humans as likely suspects.
> 
>         Now, a supernova may join the lineup. Firestone and West believe 
> that debris from a supernova
> explosion coalesced into low-density, comet-like objects that wreaked havoc 
> on the solar system long
> ago. One such comet may have hit North America 13,000 years ago, unleashing 
> a cataclysmic event that
> killed off the vast majority of mammoths and many other large North American 
> mammals. They found
> evidence of this impact layer at several archaeological sites throughout 
> North America where Clovis
> hunting artifacts and human-butchered mammoths have been unearthed. It has 
> long been established
> that human activity ceased at these sites about 13,000 years ago, which is 
> roughly the same time
> that mammoths disappeared.
> 
>         They also found evidence of the supernova explosion's initial 
> shockwave: 34,000-year-old
> mammoth tusks that are peppered with tiny impact craters apparently produced 
> by iron-rich grains
> traveling at an estimated 10,000 kilometers per second. These grains may 
> have been emitted from a
> supernova that exploded roughly 7,000 years earlier and about 250 light 
> years from Earth.
> 
>         "Our research indicates that a 10-kilometer-wide comet, which may 
> have been composed from the
> remnants of a supernova explosion, could have hit North America 13,000 years 
> ago," says Firestone.
> "This event was preceded by an intense blast of iron-rich grains that 
> impacted the planet roughly
> 34,000 years ago."
> 
>         In support of the comet impact, Firestone and West found magnetic 
> metal spherules in the
> sediment of nine 13,000-year-old Clovis sites in Michigan, Canada, Arizona, 
> New Mexico and the
> Carolinas. Low-density carbon spherules, charcoal, and excess radioactivity 
> were also found at these
> sites.
> 
>         "Armed with only a magnet and a Geiger counter, we found the 
> magnetic particles in the
> well-dated Clovis layer all over North America where no one had looked 
> before," says Firestone.
> 
>         Analysis of the magnetic particles by Prompt Gamma Activation 
> Analysis at the Budapest
> Reactor and by Neutron Activation Analysis at Canada's Becquerel 
> Laboratories revealed that they are
> rich in titanium, iron, manganese, vanadium, rare earth elements, thorium, 
> and uranium. This
> composition is very similar to lunar igneous rocks, called KREEP, which were 
> discovered on the moon
> by the Apollo astronauts, and have also been found in lunar meteorites that 
> fell to Earth in the
> Middle East an estimated 10,000 years ago.
> 
>         "This suggests that the Earth, moon, and the entire solar system 
> were bombarded by similar
> materials, which we believe were the remnants of the supernova explosion 
> 41,000 years ago," says
> Firestone.
> 
>         In addition, Berkeley Lab's Al Smith used the Lab's Low-Background 
> Counting Facility to
> detect the radioactive isotope potassium-40 in several Clovis arrowhead 
> fragments. Researchers at
> Becquerel Laboratories also found that some Clovis layer sediment samples 
> are significantly enriched
> with this isotope.
> 
>         "The potassium-40 in the Clovis layer is much more abundant than 
> potassium-40 in the solar
> system. This isotope is formed in considerable excess in an exploding 
> supernova, and has mostly
> decayed since the Earth was formed," says Firestone. "We therefore believe 
> that whatever hit the
> Earth 13,000 years ago originated from a recently exploded supernova."
> 
>         Firestone and West also uncovered evidence of an even earlier event 
> that blasted parts of the
> Earth with iron-rich grains. Three mammoth tusks found in Alaska and 
> Siberia, which were
> carbon-dated to be about 34,000 years old, are pitted with slightly 
> radioactive, iron-rich impact
> sites caused by high-velocity grains. Because tusks are composed of dentine, 
> which is a very hard
> material, these craters aren't easily formed. In fact, tests with shotgun 
> pellets traveling 1,000
> kilometers per hour produced no penetration in the tusks. Much higher 
> energies are needed: x-ray
> analysis determined that the impact depths are consistent with grains 
> traveling at speeds
> approaching 10,000 kilometers per second.
> 
>         "This speed is the known rate of expansion of young supernova 
> remnants," says Firestone.
> 
>         The supernova's one-two punch to the Earth is further corroborated 
> by radiocarbon
> measurements. The timeline of physical evidence discovered at Clovis sites 
> and in the mammoth tusks
> mirrors radiocarbon peaks found in Icelandic marine sediment samples that 
> are 41,000, 34,000, and
> 13,000 years old. Firestone contends that these peaks, which represent 
> radiocarbon spikes that are
> 150 percent, 175 percent, and 40 percent above modern levels, respectively, 
> can only be caused by a
> cosmic ray-producing event such as a supernova.
> 
>         "The 150 percent increase of radiocarbon found in 41,000-year-old 
> marine sediment is
> consistent with a supernova exploding 250 light years away, when compared to 
> observations of a
> radiocarbon increase in tree rings from the time of the nearby historical 
> supernova SN 1006," says
> Firestone.
> 
>         Firestone adds that it would take 7,000 years for the supernova's 
> iron-rich grains to travel
> 250 light years to the Earth, which corresponds to the time of the next 
> marine sediment radiocarbon
> spike and the dating of the 34,000-year-old mammoth tusks. The most recent 
> sediment spike
> corresponds with the end of the Clovis era and the comet-like bombardment.
> 
>         "It's surprising that it works out so well," says Firestone.
> 
>         - - - -
> 
>         CONTACT: Dan Krotz, Berkeley Lab Communications, 510-486-4019, 
> dakrotz_at_lbl.gov
> 
>         ABOUT THE LAB: Berkeley Lab is a U.S. Department of Energy national 
> laboratory located in
> Berkeley, California. It conducts unclassified scientific research and is 
> managed by the University
> of California. Visit our website at http://www.lbl.gov .
> 
>        Media Contact: Dan Krotz, 510-486-4019, dakrotz_at_lbl.gov
> 
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