[meteorite-list] What are the top 10 most scientificallyimportant meteorites?

From: lebofsky at lpl.arizona.edu <lebofsky_at_meteoritecentral.com>
Date: Sun, 15 Feb 2009 05:49:16 -0700 (MST)
Message-ID: <59552.71.226.60.25.1234702156.squirrel_at_timber.lpl.arizona.edu>

To continue on Sterling's theme about Mars (a little off topic from
meteorites):

Thanks to Gene Shoemaker, a number of lunar missions, and Apollo, it was
clear that the craters on the Moon were impact features and not volcanic.

However, for Mars, it was just another Moon-like body!

Mariner 4, as Sterling states, showed that Mars sort of looked like the
Moon: craters. Within a month after Apollo 11, Mariner 6 and 7 had flown
by Mars and taken a bunch more detailed images of Mars. However, they flew
by the equator and south pole of Mars. All they saw were (other than the
pole), more craters! It was not until 1971 with the Mariner 9 orbiter that
we knew that Mars was not all that Moon-like (from the point of view of
craters) when it discovered Valis Marineris and Olympus Mons.

Oh, Sterling, to date me, I WAS there for Mariner 6 and 7. My summer job
before grad school was, among other things, developing (yes we used film)
the images that came back from Mariner 6 and 7.

Larry

On Sat, February 14, 2009 8:03 pm, Sterling K. Webb wrote:
> Dear Jason, List,
>
>
>> Canyon Diablo... helped us to understand impact dynamics
>> but as to how that plays into our understanding of the evolution of the
>> solar system...it doesn't, really.
>
> Prior to the assertion that Meteor Crater was an impact
> feature, the concept of "impact" as a possible event was nil, non-existent,
> and when proposed was widely denied, pooh-pooh'ed -- an affront to the
> orderly and rational natural world.
>
> Barringer conceived of the crater as what we would call
> a particularly large impact pit, not an explosive crater, but the evidence
> drew him that way. Nininger was really the first to understand the
> possibility of impact as a geological process (without understanding the
> scale on which it was possible) and that understanding led straight to the
> late Gene Shoemaker, who single-handedly pushed a planet full of
> resistant scientists into the realization by patiently rubbing their noses
> in it for decades.
>
> Shoemaker's 1960 paper ending the 70-year dispute about
> the origin of Meteor Crater caused a sensation in geology, as it was the
> first definitive proof of an extraterrestrial impact on the Earth's
> surface. This was the first crater "proved" to be of impact origin.
> Proving that impact was a fundamental
> geological process would take decades longer. Paradigms don't always shift
> quickly.
>
> In the 1950's, the only cratered body known to science
> was the Moon, so presumably craters were an odd or unique feature in the
> Solar System, an individual characteristic
> of the Moon, not of planetary bodies generally. It was virtually
> universally understood that the 1000's of craters that covered the Moon
> were volcanic features. Our exploration of the Moon was substantially
> biased toward finding (mostly non-existent) evidence of volcanic activity.
>
>
> Even the first photos of craters on Mars in 1965 by Mariner 4
> did not budge that mindset much. This was one of those you-had-to-be-there
> moments -- the shock and disbelief caused by craters on Mars (and the
> quivers of denial that followed) was profound, like being hit between the
> eyes with a two-by-four. Well, they were probably volcanic craters
> anyway...
>
> The 1970's competed the change of paradigm and the fact of
> impact as a geological process (the title of the book that nailed it down
> firmly). That almost every body in the Solar System with a solid surface
> is cratered is now a Ho Hum fact. The reason that you, Jason, can think
> it's not important is because you are on the "modern" side of the
> conceptual divide. Until the understanding of impact, solar system
> formation models were divided between "accretion" and "coalescence." Very
> few people still believe planets formed like a dew drop any more. The
> change in formation theory walks hand-in-hand with impact theory.
>
> If Canyon Diablo was the catalyst for the recognition of
> impact processes in the Solar System -- and I think it was -- then it might
> well be the "most significant in increasing our understanding of the
> evolution of our solar system."
>
>
> Sterling K. Webb
> --------------------------------------------------------------------------
> ---
> ----- Original Message -----
> From: "Jason Utas" <meteoritekid at gmail.com>
> To: "Meteorite-list" <meteorite-list at meteoritecentral.com>
> Sent: Saturday, February 14, 2009 5:08 PM
> Subject: Re: [meteorite-list] What are the top 10 most
> scientificallyimportant meteorites?
>
>
> Hola All,
> I would have to respectfully disagree. The original post my Graham
> asked for a list of ten of "the most important meteorites with regard to
> science," and he then went on to ask: "Which ones have been the most
> significant in increasing our understanding of the evolution of our solar
> system, and what they have taught us?" I believe that the implication of
> his email was not to ask for a list of meteorites that helped to further
> our acceptance of meteoritics as a field, but rather to obtain a list of
> the ten most scientifically interesting meteorites. And, to be perfectly
> frank, if L'Aigle had been any other type (iron, stony-iron, etc), the
> outcome of the situation would have been the same. As a meteorite, while
> it did help to open our eyes as to what was actually out there, it did
> little to tell us of the history of the formation of the solar system. And
> Michael's list is more of a list of the most beautiful/interesting
> meteorites from the point of view of a collector...it's just a different
> sort of list. Did Esquel or Sylacouga contribute to our knowledge about
> the early solar system? Not particularly, but they are two of the more
> desireable meteorites around, for non-scientific reasons. Canyon Diablo
> is interesting in its own right as a crater-forming meteorite, as it
> helped us to understand impact dynamics - but as to how that plays into
> our understanding of the evolution of the solar system...it doesn't,
> really. Regards,
> Jason
>
>
>
> On Sat, Feb 14, 2009 at 1:21 PM, Michael Blood <mlblood at cox.net> wrote:
>
>> Hi Jason and all,
>> First of all, I think it should be mentioned that any such
>> List is inevitably biased.
>> Next, that said list cannot possibly "nail" a specific 10
>> meteorites. Assuming these two prospects are accepted, here are 10
>> Very respectable meteorites that would certainly merit full
>> Consideration in comprising such a list ( and at least one "why"
>> Per each:
>>
>>
>> 1) Canyon Diablo:
>> prototypical and stable iron from what was recognized as the "only"
>> impact crater for a very long time. It Can be added that it was also the
>> original site of the Nininger Museum
>>
>>
>> 2) Allende: HUGE strewn field and, at the time, more than
>> Doubled the total weight of known CR material available.
>> It was also a witnessed fall with multiple hammer stones
>> Striking homes and patios
>>
>>
>> 3) Esquel: "The queen of the Pallasites" with fantastic color,
>> Translucency, freedom from rust and in quantities large enough
>> To allow any collector to have one of the few stable Pallasites.
>>
>>
>> 4) Murchison: Providing most of the amino acids that comprise the
>> "building blocks" of life, perhaps the most "studied" of any meteorite
>> Ever and a major contributor to the angiosperm hypothesis. Again,
>> a witnessed fall and a hammer.
>>
>> 5) Portalas Valley: Perhaps a surprise in many lists, this specimen has
>> A unique physiology. Also a hammer.
>>
>>
>> 6) Weston: The first scientifically recognized meteorite in "the new
>> world." Also a hammer.
>>
>>
>> 7. L'Aigle: see below. (Also, there will be a forthcoming article on
>> the Status of L'Aigle as a hammer).
>>
>>
>> 8) Ensischeim: "The meteorite from hell." (also a hammer if you care to
>> consider a church courtyard a man made artifact). This is one of the
>> richest events ever in the "lore" of meteorites.
>>
>> 9) Sikhote-Aline: producing thousands of what are pretty much agreed to
>> be the world's most visually impressive iron individuals. Also a rare
>> Iron
>> witnessed fall.
>>
>> 10) Sylacauga: the only fully documented human striking meteorite.
>>
>>
>> I could easily add several more, but these are just my 2 cents
>> worth, anyway. I am likely wrong, as my wife repeatedly assures me I am.
>> Best wishes, Michael
>>
>>
>>
>> On 2/14/09 4:59 AM, "Martin Altmann" <altmann at meteorite-martin.de>
>> wrote:
>>
>>
>>> Hi Jason,
>>>
>>>
>>> Even though we're living in a fast world and the "modernism" of our
>>> days may give the impression, that new scientific recoveries are drawn
>>> out of the nothing. But science and ideas are always integrated in
>>> traditions and contexts and are built on earlier steps. Chladni hadn't
>>> invented the idea, that the stones may stem from outside. He connected
>>> the idea that they come from space with the fireballs, the existing
>>> stones and reports about the falls and postulated additionally, that
>>> they could survive the atmospheric travel. That approach was
>>> ridiculous for his contemporary scientists. After the period of
>>> "enlightment" it was impossible that chunks fall from
>>> sky, Newton required empty spaces between the planets or at it best,
>>> cause they were Aristotelians, they had to be atmospheric products.
>>> (Although Tycho had measured long before the parallaxes of comets, to
>>> find out that they move indeed in space).
>>>
>>> So Chladni's weird theory never would have been accepted, if there
>>> wouldn't have happened that proof, the mighty shower of L'Aigle,
>>> conveniently close to the Acad?mie de sciences.
>>>
>>> Therefore L'Aigle is for me a benchmark. Without L'Aigle no Chladni,
>>> no Schreibers, no Daubr?e...no modern meteoritics. (At least not to
>>> the advanced stage we have today).
>>>
>>> Shhht Jason, btw. Chladni isn't that much known as Father of
>>> meteoritics, but for his "Acoustics", he certainly is partially
>>> responsible for the gig tootling out from your speakers, while you're
>>> writing to the list :-)
>>>
>>> Sure it's only an ordinary chondrite, but you don't meet the meaning
>>> of this milestone, if you look with today's eyes on it.
>>>
>>>> It's an ordinary chondrite, of which there are thousands
>>>>
>>>
>>> Which gives in fact to that class an especially high scientific
>>> importance, doesn't it? The chondrites conserved the most original
>>> information about the origin of our solar system, the processes who
>>> lead to the formation of planets and they resemble much more the stuff
>>> we are all made from, than any differentiated meteorite, which tells us
>>> rather the history and development of his individual parent body. And
>>> ready we aren't yet with the chondrites. Ho many theories of chondrules
>>> genesis we have at present? Eleven? Look the recent decade, the
>>> discovery of protoplanetary discs around other stars..... and so on.
>>> Only because they are so readily available to the collectors and
>>> despite the antartcic ones so cheap like never before (yes Mrs.Caroline
>>> Smith.
>>> Fletcher,
>>> Hey, check the museum's archives, had to pay much more than you),
>>> they shouldn't be disregarded.
>>>
>>> Hey, and confess Jason! The sight of something like that
>>> http://www.chladnis-heirs.com/36.956g.jpg
>>> doesn't it made your mouth water?
>>>
>>>
>>> Well, each warehouse telescope for 30 bucks is better than that,
>>> which Galilei pointed to the Moon or Jupiter. But what for an
>>> importance it had! Would we have a Hubble Space telescope now, without
>>> that use of the lousy lense 400 years ago? (Although maybe Galileo's
>>> or Copernicus' role is maybe sometimes somewhat overrated, media
>>> stars... Copernicus' system was in practise inoperative and he had his
>>> Islamic and antique antecessors - I'm
>>> afan of Tycho, which was much more important for modern astronomy and
>>> our view of the world, as he was the first, who trumped the Islamic
>>> astronomy. Without the results of his large-scale instruments, no
>>> Kepler, no Newton,
>>> no Oberth, no Rovers on Mars, no security that the pieces in the
>>> Chladni
>>> Boxes
>>> really originated from the red planet...). Of course it's never a
>>> continuously direct and mono-causal development... Chance and accident
>>> are also factors. Allende and Murchison e.g. never would rank in the
>>> importance among the first places, if they hadn't such large tkws or
>>> if they had fallen in the oceans and if there the Moon labs weren't
>>> just ready, when they felt.
>>>
>>> But in general L'Aigle was the proof.
>>> Scientifically important, because with that fall, the concept of
>>> meteorites had to be accepted and the branch of this science was born
>>> at all.
>>>
>>> So it's my number one - only in my personal opinion of course.
>>>
>>>
>>> If we follow your criteria, Jason, everything but the very new had to
>>> be ruled out and most probably we would have to make a ranking of the
>>> so far unique - the ungrouped and similar exotics, where we don't have
>>> fully the clues, what exactly it could be.
>>>
>>> Off now, have to jump into my carriage without horses.
>>> (Hmmm was that important? Quite an unacceptable junk...
>>> http://kuerzer.de/unimport
>>> and we certainly would prefer a Lamborghini :-)
>>>
>>> Best!
>>> Martin
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>> -----Urspr?ngliche Nachricht-----
>>> Von: meteorite-list-bounces at meteoritecentral.com
>>> [mailto:meteorite-list-bounces at meteoritecentral.com] Im Auftrag von
>>> Jason
>>> Utas
>>> Gesendet: Samstag, 14. Februar 2009 02:21
>>> An: Meteorite-list
>>> Betreff: Re: [meteorite-list] What are the top 10 most
>>> scientificallyimportantmeteorites?
>>>
>>> Hola Martin,
>>> I would have to disagree - when you go that far back, you wind up
>>> dealing with meteorites that are of historic, rather than scientific
>>> interest. L'Aigle may be something of an exception because it did
>>> lead to the *scientific* acceptance of meteorites, but, from today's
>>> scientific perspective, I wouldn't call it very important, never mind
>>> giving it a place in the top ten. It's an ordinary chondrite, of
>>> which there are thousands - it's no more special than, say, Tenham or
>>> Gao - from a purely scientific point of view.
>>> One might as well call the earliest fossils found the most important,
>>> simply because they were found back in the day and led to our
>>> recognition of what they really represented...while they may be
>>> important, I would hesitate to call them extremely important from a
>>> scientific point of view. Regards,
>>> Jason
>>>
>>>
>>> On Fri, Feb 13, 2009 at 5:12 PM, Martin Altmann
>>> <altmann at meteorite-martin.de> wrote:
>>>
>>>> I choose L'Aigle as N?1.
>>>>
>>>>
>>>> Cause else they wouldn't have recognized, that Chladni was right
>>>> and that they are from space.
>>>>
>>>> Best!
>>>> Martin
>>>>
>>>>
>>>> -----Urspr?ngliche Nachricht-----
>>>> Von: meteorite-list-bounces at meteoritecentral.com
>>>> [mailto:meteorite-list-bounces at meteoritecentral.com] Im Auftrag von
>>>> ensoramanda at ntlworld.com Gesendet: Samstag, 14. Februar 2009 00:55
>>>> An: meteorite-list at meteoritecentral.com
>>>> Betreff: [meteorite-list] What are the top 10 most scientifically
>>>> importantmeteorites?
>>>>
>>>> Hi all,
>>>>
>>>>
>>>> Just thought it might be interesting to discover list members
>>>> opinions on what they would choose as the most important meteorites
>>>> with regard to science? Which ones have been the most significant in
>>>> increasing our understanding of the evolution of our solar system,
>>>> and what they have taught us?
>>>>
>>>> Graham Ensor, UK.
>>>> ______________________________________________
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>>>>
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>>
>>
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Received on Sun 15 Feb 2009 07:49:16 AM PST