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Chance of asteroids hitting earth very slim - Russian astronomers
INterfax ^ | May 8 2006 12:01PM

Posted on 05/08/2006 10:46:41 AM PDT by x5452

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To: Bon mots

Meteor crater from from a meteroid - not an asteroid.

" a huge iron-nickel meteorite or dense cluster of meteorites, estimated to have been about 150 feet across and weighing several hundred thousand tons, struck the rocky plain with an explosive force greater than twenty million tons of TNT. "


41 posted on 05/08/2006 1:33:41 PM PDT by LM_Guy
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To: Bon mots

Here is a great map of the Earth's dart board for Meteroids and Asteroids.

http://www.lpi.usra.edu/publications/slidesets/craters/images/02_DISTRIBUTION_MAP.JPG


42 posted on 05/08/2006 1:43:22 PM PDT by LM_Guy
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To: bruin66
Not necessarily. An asteroid is capable of outgassing which could affect its orbit. Whether or not is is going to outgas is determined by the makeup of the asteroid and its orbit in relation to the sun. All of these things are governed by physical laws. there is no randomness involved. As I said, uncertainty only comes in because we can't possible measure and forecast these things for every asteroid out there (especially those that we don't even know about) for the next 100 years. However, our inability to forecast does not change the fact that asteroids obey physical laws.
43 posted on 05/08/2006 1:47:52 PM PDT by freakboy
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To: Tzimisce

Are they still debunking it? I thought Putie-put signed on to Kyoto. After the EU bribed him, that is.


44 posted on 05/08/2006 1:51:54 PM PDT by Calvin Locke
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To: Calvin Locke

I beleive Russia's stance on that (privatly) was that no one was going to follow such a stupid law anyway so why not cash in?


45 posted on 05/08/2006 5:47:04 PM PDT by x5452
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To: Cautor
I don't think so. The evidence is overwhelmingly against an impact wiping out the Dinosaurs

Here's just some of it

1) Southern Hemisphere species were equally devastated as the Northern Hemisphere ones. This makes absolutely no sense. An asteroid hitting in the Northern Hemisphere should cause more devastation in the Northern Hemisphere.

2) Freshwater Species including amphibians (100% survival rate) did quite well. One only has to come to upstate NY to see the damage done to freshwater species by acid rain, Some lakes are completely dead. If the relatively tiny amount of acid rain put out by Midwestern plants can cause all that damage then the massive amounts of acid rain produced by a global nuclear winter would have had devastating effects all all freshwater species. That is not what we see.

3) Plankton

a)   Diatoms. The K-T event did not much affect the diatoms. Harwood (1988), based on studies from Seymour Island, eastern Antarctic Peninsula, the first to record siliceous microfossil assemblages across a K-T boundary sequence, notes that diatom survivorship across the K-T boundary was above 90 percent. Resting spores increase from 7 percent below to 35 percent across the K-T boundary.

b)  Dinoflagellates. Dinoflagellates also were little affected by the K-T event (Bujak and Williams, 1979). Brinkhuis and Zachariasse (1988) record no accelerated rates of extinction across the K-T boundary in Tunisia. Nor does Hultberg (1986) in Scandinavia. Danish dinoflagellates responded more by appearance of new species than by extinctions (Hansen, 1977), as did Seymour Island assemblages (Askin, 1988).

c) Yes other plankton did suffer massive extinctions but it wasn't because of the Asteroid or K-T event.

Marine calcareous microplankton, the coccolithophorids and planktonic foraminifera, were hit hardest of all by the K-T event. Thierstein (1981) proposes that the coccolithophorids extinctions were the most severe plankton extinction event in geologic history; via a "deconvolution" process, Thierstein (1981, 1982) reduced a Cretaceous-Tertiary "transition," in which Cretaceous assemblages were replaced by "new" Tertiary taxa, to an instantaneous catastrophe. Perch-Nielsen et al. (1982) note that the "catastrophic event"at the K-T boundary did not result in geologically instant extinction of the calcareous nannoplankton, and that most Cretaceous species survived the event. At DSDP Site 524, a sample above the K-T boundary contains 90 percent Cretaceous species. Isotopic analyses indicated that the Cretaceous species were not reworked specimens, but represented survivors of the K-T event that continued to reproduce in the earliest Tertiary oceans. The relict species became extinct some tens of thousands of years after K-T boundary time, probably via environmental stresses.

d) Antia and Cheng's (1970) work on survival times of phytoplankton species in complete darkness indicate that 1 month of complete blackout would produce 13 percent extinction, 3 months 68 percent extinction , and 6 months 81 percent. Thus, the 6 month to 1 year global blackout predicted by Wolbach et al. (1985) would have obliterated diatoms, dinoflagellate, and coccolithophorids precisely at the K-T boundary. A blackout event is not reflected in the algal record.

So please tell me how did photoplankton who depend on sunlight for their very exsistance not only not die out but actually thrive during a global blackout??

e) Another interesting thing about plankton, Microfossils were actually found in the Chicxulub crater itself!!! and even though they are essentially at "Ground Zero" they show no ill effects.

4) Reptiles would have suffered greatly if an Asteroid struck however they seem to have cruised through the K-T with no problems.

a)  Turtles  "The Hell Creek and Tullock formations contain many turtles, and span the Cretaceous-Tertiary boundary. Over 3000 specimens were counted on a modified minimum number basis from 510 localities. At least 15 of about 19 Cretaceous genera and subgenera survive into the Paleocene. The magnitude of the change in diversity is less than or comparable to examples within the Tertiary. These data do not support a unique comprehensive extinction at the end of the Cretaceous as postulated on the basis of Iridiurn concentrations."

My link is gone but the quote is from: Hutchison, JH. H., and J. D. Archibald. 1986. Diversity of turtles across the Cretaceous/Tertiary boundary in northeastern Montana. Palaeogeography, Palaeoclimatology, Palaeoecology 55:1-22.

b) The four crocidilian families survived seemingly unaffected through the K-T boundary.

Most notable is the American Alligator whose ancestors were living at the time of Cretaceous right at ground zero

This is the skull of an extinct animal closely related to living crocodylians (U.S. National Museum 22039). It comes from the middle Cretaceous (roughly 100 million years ago) of central Texas. It shows the occlusal pattern seen in the common ancestor of alligators and crocodiles.

So they were there!

Even forgetting about the implausibility of Alligators who are very cold sensitive surviving a nuclear winter, How did they survive the blast and the follow up tsunami an Asteroid would have caused?

5) Tropical Honeybees also would have been wiped out immediately under the impact scenario. They survived unscathed.

6) Dinosaurs

a) Dinosaurs were living near the poles so they were capable of surviving cold temps, So if other animals could survive a global nuclear winter why couldn't they?

b)  Dinosaurs were slowly going extinct before the K-T event and probably most of them were gone by it.

Sullivan (1987) For the 19 dinosaurian families (33 to 39 species) existing in the last 20 million years of the Cretaceous, most disappeared before K-T boundary time, and eight at the K-T boundary. The eight families are represented by 12 species in the final 3 million year of the Cretaceous, and most of the species by only a few specimens (two to 10, average 5.7).

c) Few dino fossils are found in the K-T boundary. Fossilization maybe a rare process mostly due to scavengers scattering the bones. However if an Asteroid strike instantly wiped out the dinosaurs than there would have been too many dead bodies for even the scavengers  to get them all, so their should be large amounts of fossils in the K-T boundary 

d) Actually there is evidence that some dinosaurs made it into the Tertiary.  

e) One group of Dinosaurs did make it and lives to this very day, We call them Birds.

7) The Thin Layer of Iridium:

That "Thin" layer of iridium as it is described represents 10,000-100,000 years of sediment. How on Earth could iridium (a heavy metal no less) stay up in the atmosphere that long? It would at most wash out within months if not weeks or days.

8) Iridium spikes aren't uncommon:

      a) Notice the larger than the KT iridium spike way later in the Paleocene (on the upper right side)

Now, If a 10 mile wide Asteroid caused the IR Spike for the KT-Boundary. How many more times larger would an Asteroid have to be to cause that bigger spike later on? How come that one didn't cause mass extinctions?

b) There are multiple Iridium at some locations

For example, Lattengebirge, Bavarian Alps, has three iridium anomalies, below, at, and above, the K-T boundary (Graup and Spettel, 1989). The oldest anomaly antedates the K-T boundary by 14,000-9,000 years. To which of these anomalies might the Rocky Mountain (and other) "K-T boundary" iridium spike be isochronous, if any? The Brazos River, Texas, locality has two iridium spikes, one at the K-T boundary, and one below (Ganapathy et al., 1981). At Gubbio, Italy, both the iridium and shocked minerals do not occur as a sharp K-T spike; enrichment begins 2 m below the boundary and extends 2 m above it for a total of about 400,000 years (Crockett et al, 1988; Rocchia et al., 1989)

8) Volcanos can also produce Iridium spikes.

For example the 1783 Lakigigar eruption produced an 18-fold iridium enrichment in the ice cores of Greenland which is well within the range of the iridium spikes of the K-T event. So volcanic activity can produce iridium spikes and boy was there monstrous volcanic activity during the KT. The Deccan traps of India and Pakistan- (covering 500,000 sq. km and up to 2 km thick) , southern Brazil , western U.S, etc which was more than enough to produce the iridium spikes. Plus the volcanic activity unlike a one shot asteroid lasted a long time so it could have been laying down iridium over 10,000-100,000 years. Koeberl (1989) also reports iridium concentrations up to 7.5 ppb in volcanic dust bands in blue ice fields from Antarctica.

9) Iridium is missing from the Chicxulub crater itself!!!!! 

How can an Asteroid or whatever (It's still not proven to be a meteor crater and it's looking like one less and less) that caused the Chicxulub crater produce a iridium spike around the world when it didn't contain iridium?  

10) Arsenic, antimony, and selenium levels are very high in the K-T Boundary, These elements are rare in meteorites (but not in volcanoes).  

None of these makes sense under the impact hypothesis

46 posted on 05/09/2006 2:17:05 AM PDT by qam1 (There's been a huge party. All plates and the bottles are empty, all that's left is the bill to pay)
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To: x5452

"Smirnov dismissed as unfounded reports that a giant asteroid could strike the Earth in the summer of 2008 and said this is clear "

Now, how are you going to trust a guy whose name is Smirnov.


47 posted on 05/09/2006 2:33:46 AM PDT by FastCoyote
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To: x5452

I ain't worried about the next hundred years.

A little nervous about the next hundred days, though...

http://neo.jpl.nasa.gov/cgi-bin/db_shm?sstr=73p&group=all&search=Search


48 posted on 05/09/2006 2:38:52 AM PDT by djf (Bedtime story: Once upon a time, they snuck on the boat and threw the tea over. In a land far away..)
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To: LM_Guy
Not that I have heard of, in fact I just watched a science show on the History Channel last night which stated the evidence is stronger than ever and they even know / speculate where it hit.

If you saw the same program I saw, then you would have seen both Bob Bakker and Jack Horner (The top 2 bigwigs in palaeontology) come on afterwards and explain why it's bunk.

And the Asteroid hypothesis has been debunked since 1986 when Bob Bakker published The Dinosaur Heresies

Here's two good reads on the subject

Great Balls of Fire: Has Science's Doomsday Scenario bitten the Dust?

Impact Winter in the Global K-T Extinctions: No Definitive Evidences

You won't find too many palaeontologist in favor of the Asteroid hypothesis, the promoters are mostly Geologist, Physicist and Astronomers who like their face time in front of the media (and trips to Cancun) . And unfortunately many of the pro-Asteroid group has behaved worse than the Creationist.

For example see the link I posted about how Iridium is missing from the Chicxulub crater itself!!!!! 

Now the evidence this guy found clearly overwhelmingly debunks the Asteroid theory, yet this guy blatantly just dismisses it.

Quote right from the conclusion in the paper

If we exclude the extremely implausible assumption that the K/T boundary is not related to the Chicxulub impact event,

Like Hey!!!, who says you can do that? That's not science. You can't just exclude conclusions because you don't like it.

Here's another example of Pro-Asteroid scientist playing tricks

49 posted on 05/09/2006 3:03:45 AM PDT by qam1 (There's been a huge party. All plates and the bottles are empty, all that's left is the bill to pay)
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To: LM_Guy
Relic of ancient asteroid found ..punched 160km-wide (100 miles) hole in the Earth's surface
50 posted on 05/11/2006 12:34:49 AM PDT by Bon mots
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engarde!

Very Large Meteorite Fell Down in Siberia
Pravda | 15:33 2003-03-18
Posted on 06/13/2004 6:24:49 PM EDT by ckilmer
http://www.freerepublic.com/focus/f-news/1152933/posts


51 posted on 05/25/2006 7:02:55 AM PDT by SunkenCiv (https://secure.freerepublic.com/donate/)
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SIBERIA METEORITE FLATTENS 40 SQ MILES
The Times | 7 June 2003 | Robin Shepherd
Posted on 06/09/2003 8:25:21 PM EDT by Mike Darancette
http://www.freerepublic.com/focus/f-news/926025/posts


52 posted on 05/25/2006 7:05:28 AM PDT by SunkenCiv (https://secure.freerepublic.com/donate/)
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To: 75thOVI; agrace; aimhigh; Alice in Wonderland; AndrewC; aragorn; aristotleman; Avoiding_Sulla; ...
Note: this topic was posted 5/8/2006. And if they didn't look ridiculous in light of Tunguska, how about now? Thanks x5452.

53 posted on 01/25/2014 8:34:41 AM PST by SunkenCiv (;http://www.freerepublic.com/~mestamachine/)
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