[meteorite-list] Scientist Warns Massive Asteroid CouldHitEarthin 2182

From: countdeiro at earthlink.net <countdeiro_at_meteoritecentral.com>
Date: Thu, 29 Jul 2010 10:39:56 -0400 (EDT)
Message-ID: <31264863.1280414396535.JavaMail.root_at_wamui-june.atl.sa.earthlink.net>

Thank you, Sterling

Like is so famously said..."it ain't whether, but when." Thanks also for the very interesting and informative link.

Guido

-----Original Message-----
>From: "Sterling K. Webb" <sterling_k_webb at sbcglobal.net>
>Sent: Jul 29, 2010 5:10 AM
>To: countdeiro at earthlink.net, Stuart McDaniel - Action Shooting Supply <actionshooting at carolina.rr.com>, Thunder Stone <stanleygregr at hotmail.com>, meteorite-list at meteoritecentral.com
>Subject: Re: [meteorite-list] Scientist Warns Massive Asteroid CouldHitEarthin 2182
>
>List, Count,
>
>Ejecta get sorted by mass -- big chunks near the crater,
>then medium chunks in the middle distance and so on.
>At about 300 miles from impact, there is still a noticeable
>dustfall from an impact this size. And the smallest particles
>get blown into the atmosphere world-wide as micron-sized
>dust.
>
>The statistical average speed for ejecta is always less than
>the impact velocity because a lot of energy is used up in
>the fireball, vaporizing the impactor, vaporizing a roughly
>equal mass of target (Earth!), melting target rocks, and lastly,
>fracturing target rocks to be ejected.
>
>The chances of a piece of ejecta getting kicked up to even
>sub-orbital velocity is small, but with this many pieces in
>play, it MIGHT happen to a very small number of pieces. So,
>no "large quantities of ejecta" would behave as you asked.
>
>The only real-world example of high speed ejecta is tektites,
>which "seem to be" vaporized target rock that condenses into
>liquid and cools to a plastic glass very quickly, probably
>above the atmosphere. They can travel up to half an Earth
>diameter. But that's the only example we have to go by,
>and it's mysterious -- why doesn't every impact produce
>tektites?
>
>But for 99.9% of ejecta, it's the same old story everywhere
>on every planet. Google up pictures of "ejecta blanket."
>http://www.google.com/images?hl=en&q=ejecta%20blanket&um=1&ie=UTF-8&source=og&sa=N&tab=wi&biw=967&bih=640
>
>Big, blocky chunks just outside the rim, tapering off to
>dust at the edges. That's the interesting thing about kinetic
>events -- they're all the same. Once you get up to a good
>size, the particular characteristics don't matter much.
>
>In this size of event, an equal weight of impacting ice, or rock,
>or iron, or feathers, or rocky road ice cream -- they would
>all leave an almost identical crater. All that counts is the
>total kinetic energy.
>
>Objects get blasted off planets. Mars meteorites somehow
>got off Mars. Lunar meteorites somehow got off the Moon.
>There are even folks who think a chunk of Mercury could
>somehow get off Mercury (which chunk is the question).
>Moreover, they seem to sometimes do it without being
>shocked, possibly by being sucked up the tube of vacuum
>formed when the impactor blows through the atmosphere.
>No one knows how exactly, but it happens, I suspect, as
>a rare event.
>
>Not to be callous, but an eight-mile crater is a "medium"
>impact, with local effects, not regional effects, not continental
>effects, not world-threatening effects. But like any explosion,
>it is nastier the closer you happen to be to it.
>
>It could take out about half of the state of Iowa, for example.
>Beyond Iowa's borders, damage would be minimal.
>
>Still, Iowa...
>
>
>Sterling K. Webb
>--------------------------------------------------------------------------------
>----- Original Message -----
>From: <countdeiro at earthlink.net>
>To: "Sterling K. Webb" <sterling_k_webb at sbcglobal.net>; "Stuart
>McDaniel - Action Shooting Supply" <actionshooting at carolina.rr.com>;
>"Thunder Stone" <stanleygregr at hotmail.com>;
><meteorite-list at meteoritecentral.com>
>Sent: Thursday, July 29, 2010 12:13 AM
>Subject: Re: [meteorite-list] Scientist Warns Massive Asteroid
>CouldHitEarthin 2182
>
>
>Sterling,
>
>With the understanding that the impactor is of the size you described in
>your last.
>
>Could there be significant property damage and human casualties outside
>the 100 mile diameter from the fall of matter propelled to great heights
>and trajectories?
>
>Is it plausible that large quantities of ejecta could be propelled into
>low earth, rapidly decaying orbits and re-enter to cause significant
>secondary impact damage vicariously over the earth?
>
>Do you think some material could escape the earth's gravity to become
>meteoroids?
>
>Count Deiro
>IMCA 3536
>
>-----Original Message-----
>>From: "Sterling K. Webb" <sterling_k_webb at sbcglobal.net>
>>Sent: Jul 28, 2010 11:17 PM
>>To: Stuart McDaniel - Action Shooting Supply
>><actionshooting at carolina.rr.com>, Thunder Stone
>><stanleygregr at hotmail.com>, meteorite-list at meteoritecentral.com
>>Subject: Re: [meteorite-list] Scientist Warns Massive Asteroid Could
>>HitEarthin 2182
>>
>>List, Stuart,
>>
>>An eight-mile complex crater with a depth of
>>about a half-mile. Will take 100% casualties out to
>>about 35 miles and 70% casualties out to 60 miles.
>>High-speed ejecta 1 cm and up will reach out to
>>about 100 miles. Within the inner 75-mile-diameter
>>circle, expect the destruction of almost everything
>>and the death of almost everybody.
>>
>>Even at 60 miles away, the fireball will deliver about
>>4 megajoules per square meter for about 3.5 minutes,
>>enough to produce deep third degree burns, and
>>cause trees and grass to ignite, as well as wood and
>>part-wood structures. Masonry structures would
>>collapse from the overpressure; steel structures
>>would survive best.
>>
>>An ocean strike would form a smaller crater in the
>>seafloor but the thermal effects would be about the
>>same (actually a little worse). The tsunami would
>>be between 250 and 450 feet high. It would be
>>world-wide, reach far inland in some areas, and
>>would likely circle the globe more than once.
>>
>>Either a land or sea strike would likely result in
>>comparable damages. Numbers would depend on
>>the population and structural density of the
>>area. Middle of the Sahara? Thousands. South
>>China Coast? Tens of millions.
>>
>>Highly unlikely that any of the materials you
>>might gather after the region of the crater stopped
>>glowing would be part of the impactor, almost all
>>of which would vaporize. Terrestrial fragments
>>would dominate the region.
>>
>>
>>Sterling K. Webb
>>-------------------------------------------------------------------
>>----- Original Message -----
>>From: "Stuart McDaniel - Action Shooting Supply"
>><actionshooting at carolina.rr.com>
>>To: "Thunder Stone" <stanleygregr at hotmail.com>;
>><meteorite-list at meteoritecentral.com>
>>Sent: Wednesday, July 28, 2010 9:03 PM
>>Subject: Re: [meteorite-list] Scientist Warns Massive Asteroid Could
>>HitEarthin 2182
>>
>>
>>Not a mathematician are you?? LOL..........it's 172 years. Bet that
>>will
>>make a nice strewn field!!!
>>
>>Stuart McDaniel
>>Lawndale, NC
>>Secr.,
>>Cleve. Co. Astronomical Society
>>----- Original Message -----
>>From: "Thunder Stone" <stanleygregr at hotmail.com>
>>To: <meteorite-list at meteoritecentral.com>
>>Sent: Wednesday, July 28, 2010 6:23 PM
>>Subject: [meteorite-list] Scientist Warns Massive Asteroid Could Hit
>>Earthin
>>2182
>>
>>
>>
>>Wow - that's only 72 years from now... Don't think I'll be around
>>
>>Greg S.
>>
>>
>>http://www.foxnews.com/scitech/2010/07/28/massive-asteroid-hit-earth-warn-scientists/?test=faces
>>
>>
>>
>>Scientist Warns Massive Asteroid Could Hit Earth in 2182
>>
>>A large asteroid in space that has a remote chance of slamming into the
>>Earth would be most likely hit in 2182, if it crashed into our planet
>>at
>>all, a new study suggests.
>>
>>The asteroid, called 1999 RQ36, has about a 1-in-1,000 chance of
>>actually
>>hitting the Earth, but half of that risk corresponds to potential
>>impacts in
>>the year 2182, said study co-author Mar?a Eugenia Sansaturio of the
>>Universidad de Valladolid in Spain.
>>
>>Sansaturio and her colleagues used mathematical models to determine the
>>risk
>>of asteroid 1999 RQ36 impacting the Earth through the year 2200. They
>>found
>>two potential opportunities for the asteroid to hit Earth in 2182.
>>
>>The research is detailed in the science journal Icarus.
>>
>>The asteroid was discovered in 1999 and is about 1,837 feet (560
>>meters)
>>across. A space rock this size could cause widespread devastation at an
>>impact site in the remote chance that it hit Earth, according to a
>>recent
>>report by the National Academy of Sciences.
>>
>>
>>Scientists have tracked asteroid 1999 RQ36's orbit through 290 optical
>>observations and 13 radar surveys, but there is still some uncertainty
>>because of the gentle push it receives from the so-called Yarkovsky
>>effect,
>>researchers said.
>>
>>The Yarkovsky effect, named after the Russian engineer I.O. Yarkovsky
>>who
>>proposed it around 1900, describes how an asteroid gains momentum from
>>thermal radiation that it emits from its night side. Over hundreds of
>>years,
>>the effect's influence on an asteroid's orbit could be substantial.
>>
>>Sansaturio and her colleagues found that through 2060, the chances of
>>Earth
>>impacts from 1999 RQ36 are remote, but the odds increase by a magnitude
>>of
>>four by 2080 as the asteroid's orbit brings it closer to the Earth.
>>
>>The odds of impact then dip as the asteroid would move away, and rise
>>in
>>2162 and 2182, when it swings back near Earth, the researchers found.
>>It's a
>>tricky orbital dance that makes it difficult to pin down the odds of
>>impact,
>>they said.
>>
>>"The consequence of this complex dynamic is not just the likelihood of
>>a
>>comparatively large impact, but also that a realistic deflection
>>procedure
>>(path deviation) could only be made before the impact in 2080, and more
>>easily, before 2060," Sansaturio said in a statement.
>>
>>After 2080, she added, it would be more difficult to deflect the
>>asteroid.
>>
>>"If this object had been discovered after 2080, the deflection would
>>require
>>a technology that is not currently available," Sansaturio said.
>>"Therefore,
>>this example suggests that impact monitoring, which up to date does not
>>cover more than 80 or 100 years, may need to encompass more than one
>>century."
>>
>>By expanding the timeframe for potential impacts, researchers would
>>potentially identify the most threatening space rocks with enough time
>>to
>>mount deflection campaigns that are both technologically and
>>financially
>>feasible, Sansaturio said.
>>
>>______________________________________________
>>Visit the Archives at
>>http://www.meteoritecentral.com/mailing-list-archives.html
>>Meteorite-list mailing list
>>Meteorite-list at meteoritecentral.com
>>http://six.pairlist.net/mailman/listinfo/meteorite-list
>>
>>
>>______________________________________________
>>Visit the Archives at
>>http://www.meteoritecentral.com/mailing-list-archives.html
>>Meteorite-list mailing list
>>Meteorite-list at meteoritecentral.com
>>http://six.pairlist.net/mailman/listinfo/meteorite-list
>>
>>______________________________________________
>>Visit the Archives at
>>http://www.meteoritecentral.com/mailing-list-archives.html
>>Meteorite-list mailing list
>>Meteorite-list at meteoritecentral.com
>>http://six.pairlist.net/mailman/listinfo/meteorite-list
>
Received on Thu 29 Jul 2010 10:39:56 AM PDT