[meteorite-list] How to discover asteroid impacts

From: Sterling K. Webb <sterling_k_webb_at_meteoritecentral.com>
Date: Sat Mar 11 22:57:40 2006
Message-ID: <009401c64589$14ab6210$1a57e146_at_ATARIENGINE>

Hi, Darren, List

    I've been searching the desert for additional craters, too.
Here's a couple more candidates beside the two mentioned
on the astroseti.org website.

    Let me stress that I am neither a geologist nor an aerial
photointerpreter, so these are just what looks good to me.

    First, 37 miles WSW of the newly noticed Kebira crater,
at 24 deg 34' North and 24 deg 24' East, is a 2.57 mile
crater. It has no central uplift and has been cut by ancient
stream courses, so that its interior is at the same level as
the surrounding terrain. The rim is raised 100 to 300 feet.
There are fairly clear traces of an outer ring with a diameter
of approximately 9 miles. The ancient eroded outcrops in
which it lies all have features that run a little west (east)
of north (south). The crater's arcuate features cut right
across the "lie of the land."
    Frankly, it looks as much (or more) like a crater than
Kebira itself. The imagery I can access is not detailed
enough to examine the rim for upturned strata.

    Secondly, at 22 deg North and 16.5 deg East, there are
a number of features that are eliptical in nature stretching
to the west of the indicated location. This is a region in which
old outcrops running almost north-south are being "submerged"
in the Great Sand Sea. Many features are irregular ovals filled
with sand to the same level as the surrounding terrain, are
probably former ancient lakes, and lie at the margins of the
outcrops, as you would expect lakes to do.
    But the first of them, at 22 deg North and 16.5 deg East,
is chopped right across and completely through a prominent
outcrop. It is an very regular ellipse with a 5.1 mile major axis
and a 3.9 mile minor axis. Its floor is 300 feet below the
surrounding terrain (despite the blowing sand which should
have filled it in, I would have thought). What makes me consider
it a candidate is the way it is cut through the elevated eroded
mountains like it was punched out by a giant cookie cutter,
hardly the way (or place) a lake would have formed.

    This region is rife with circular features, of course, when
viewed at a distance, but with closer inspection resemble true
craters not at all. I've "zoomed" through 40 or 50 of them and
these two are the only ones that seem to be craters (to me,
at least). The List being replete with individuals with lots of
geological expertise, tell me if you think there are more obvious
explanations for these features than the energetic expression
of a "rock from space."


Sterling K. Webb
--------------------------------------------------------------------------------
----- Original Message -----
From: "Darren Garrison" <cynapse_at_charter.net>
To: <Meteorite-list_at_meteoritecentral.com>
Sent: Saturday, March 11, 2006 9:53 AM
Subject: [meteorite-list] How to discover asteroid impacts


http://www.astroseti.org/impacts.php
______________________________________________
Meteorite-list mailing list
Meteorite-list_at_meteoritecentral.com
http://six.pairlist.net/mailman/listinfo/meteorite-list
Received on Sat 11 Mar 2006 10:57:27 PM PST