[meteorite-list] Vesta & HED's

From: Benjamin P. Sun <bpsun2009_at_meteoritecentral.com>
Date: Sun, 13 May 2012 10:35:51 -0400
Message-ID: <CAE1PX846txdXoFovLRGQcGyF8uotET0BCfExskzAm3Z8kjHmEA_at_mail.gmail.com>

Yes, but aren't the relatively few non-Vesta eucrites classified as
ungrouped achondrites or anomalous eucrites?(if not then they should
be)
So I would like to think that there is already the notion that there
may be a few rare exceptions.

On 5/13/12, MstrEman <mstreman at gmail.com> wrote:
> Keep in mind that there are now some non-Vesta originating eucrites
> identified. So the pass state of knowledge holding that all HEDs were
> from Vesta should be qualified with a caveat that "Most all eucrites
> are from Vesta" or "with rare exception..." or "all most all..."
>
> Elton
>
> On 5/11/12, Benjamin P. Sun <bpsun2009 at gmail.com> wrote:
>> This is not a surprise to me... or to most of us. But it may be "news"
>> to some of you out there..
>>
>>
>> http://www.jpl.nasa.gov/news/news.cfm?release=2012-132
>>
>> https://asunews.asu.edu/20120510_Vesta
>>
>> "Data also confirm a distinct group of meteorites found on Earth did,
>> as theorized, originate from Vesta. The signatures of pyroxene, an
>> iron- and magnesium-rich mineral, in those meteorites match those of
>> rocks on Vesta's surface. These objects account for about 6 percent of
>> all meteorites seen falling on Earth.
>>
>> This makes the asteroid one of the largest single sources for Earth's
>> meteorites. The finding also marks the first time a spacecraft has
>> been able to visit the source of samples after they were identified on
>> Earth."
>>
>> ?Dawn observations enabled us to recognize that there are actually TWO
>> large basins at the south pole, an older one named ?Veneneia? and a
>> younger one named ?Rheasilvia?,? explains Williams.
>>
>> The Rheasilvia basin dominates the geology of Vesta, as the basin
>> itself and its impact ejecta cover most of the southern hemisphere.
>> The center of Rheasilvia has a central peak taller than Mt. Everest or
>> Mauna Loa on Earth, similar in height to Olympus Mons on Mars. This
>> basin appears to have excavated into the mantle of Vesta, exposing
>> material spectrally similar to diogenite meteorites; Vesta?s crust is
>> spectrally similar to eucrite and howardite meteorites, thus
>> confirming that Vesta and its family of asteroids are the source of
>> the howardite-eucrite-diogenite (HED) family of basaltic achondrite
>> meteorites.
>>
>> ?For most planets and moons we see the pictures first, then have
>> samples collected later to confirm our geologic interpretations. In
>> the case of Vesta, thanks to the HED meteorites, we have the samples
>> first, and must try to relate them to our emerging geologic picture of
>> Vesta from the Dawn mission,?
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>
Received on Sun 13 May 2012 10:35:51 AM PDT