[meteorite-list] SMART-1 impact

From: Sterling K. Webb <sterling_k_webb_at_meteoritecentral.com>
Date: Mon Sep 4 23:05:08 2006
Message-ID: <006a01c6d098$15441e70$86e18c46_at_ATARIENGINE>

Hi, Rob,

    Gee, Rob, now I know why you find things!
The 11th frame has the impact. The 12th frame
has a brightened patch two pixels wide and five
pixels high. The 13th frame has a less bright but
still over-brightened patch two pixels wide and
two pixels high, which are in the same position
as the upper 4 pixels of the 12th frame patch.
In the 14th frame and the 11th frame, this same
area is completely "cool," much grayer.

    So, the heating effect persisted for more than
30 seconds (the frame rate was 15 seconds
exposure per frame, and you have to read out
the chip between frames).

    If anyone else wants to see the effect, load
the animated gif file into Photoshop which will
separate the frames as layers. I enlarged the
impact point to a 2000% view in a window framed
around the edges of the flash in frame 11, then
switched from layer to layer to layer.

    Rob, if you found this with your bare eyeballs,
from just watching the gif, I congratulate you. It's
invisible to me at that size!

    A little poking around in the ESA website
reveals that SMART-1 came in from the north in
a polar orbit, so I will hypothesize that the top four
pixels where the heat persists through two frames
is the impact point itself and the six pixels "below"
it are the "splash" of the low inclination impact,
hot debris and ejecta being thrown out in a blanket
that extends mostly to the south of the crater.

    You know how I like to hypothesize...

    As to pixel size translation to actual ground
size, we can forget it -- not enough data. Instead
of the "megacam" they talk about on the CFHT
website, they used their new "WIRcam," a wide
angle IR sensor, so no idea of pixel-ground size.
However, Lehmann C crater is 16 kilometers in
diameter and is eight pixels wide in the image, so
-- just a wild guess -- 2 kilometers to the pixel?

    Just in case anyone has a telescope big enough
to search for a 10-meter crater (like a 10-meter
scope in orbit, say), the ESA website has a very
detailed Observing Guide to the impact site:

    The reason Rob finds things? He looks for them!

Sterling K. Webb
----- Original Message -----
From: "Matson, Robert" <ROBERT.D.MATSON_at_saic.com>
To: <MexicoDoug_at_aim.com>; <meteorite-list@meteoritecentral.com>
Sent: Monday, September 04, 2006 8:19 PM
Subject: [meteorite-list] SMART-1 impact

> Hi Doug and List,
> I don't know if I'm the first to notice this but the effect of
> the lunar impact is still visible in the Canada-France-Hawaii
> telescope image 15 seconds after impact. Check the frame
> immediately after the bright impact frame in the movie below,
> and you'll see a small lingering white spot centered exactly
> on where the impact flash was in the prior frame:
> http://www.cfht.hawaii.edu/News/Smart1/anim2.gif
> <http://www.cfht.hawaii.edu/News/Smart1/anim2.gif>
> --Rob
Received on Mon 04 Sep 2006 11:05:03 PM PDT

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