[meteorite-list] Very Interesting Photo- Tektite Related

From: Aubrey Whymark <tinbider_at_meteoritecentral.com>
Date: Fri, 25 Mar 2011 07:42:28 +0000 (GMT)
Message-ID: <172317.38764.qm_at_web28504.mail.ukl.yahoo.com>

Hi

Interesting, but I don't think this supports any tektite formation theories. Tektites were either plastically deformed when proximal, spalled when medial or ablated and then often spalled when distal.

Rain drops are, however, very informative about proximal tektites, which basically follow the same formation method with two big difference: Tektites cool and 'freeze' in transient morphologies and the tektite 'liquid' is of different viscosity (continually becoming more viscous as temperature drops). These transient tektite morphologies comprise discs and teardrops. Rain drops are spherical - when larger they become concavo-convex discs and then cascade into smaller spheres. If only the early tektite researchers had studied proximal tektites and not distal forms - their conclusions on the aerodynamics would have to be that tektites either formed on the Earth or that the moon has a significant atmosphere (or that tektites arrived from the moon in a huge molten blob which was disrupted during re-entry - but that's getting desperate).

Ice cubes give an insight to tektite formation - they cool from the outside-in thus giving a radial pattern internally. Tektites also cool from the outside-in and have a radial internal structure with bubble complexes often trapped in the centre.

Hail stones grow from the inside out and so have a concentric structure unlike tektites. These hailstones pictured are weird - they look like hailstones that have had icicles grow on them. They form in a totally different way to tektites, but interesting nonetheless. Tektites do not grow - they distort, spall (explosively fragment and lose mass) or ablate (lose mass by material melting and flowing from the specimen) during re-entry.

Found an interesting paper on these lobed hailstones here:
http://journals.ametsoc.org/doi/pdf/10.1175/1520-0469%281970%29027%3C0667%3ALSOH%3E2.0.CO%3B2

Regards, Aubrey
www.tektites.co.uk



--- On Thu, 24/3/11, Mike Groetz <mpg4444 at gmail.com> wrote:

> From: Mike Groetz <mpg4444 at gmail.com>
> Subject: [meteorite-list] Very Interesting Photo- Tektite Related
> To: "Meteorite List" <meteorite-list at meteoritecentral.com>
> Date: Thursday, 24 March, 2011, 12:17
> List-
> ? ?Check out this ice hail photo. It really substantiates
> the theories
> behind tektite formation.
>
> http://www.coasttocoastam.com/photo/category/photo-of-the-day
>
> ? Have a good day.
>
> Mike
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Received on Fri 25 Mar 2011 03:42:28 AM PDT