[meteorite-list] Moon rock?

From: Randy Korotev <korotev_at_meteoritecentral.com>
Date: Mon, 07 May 2007 08:56:13 -0500
Message-ID: <200705071356.l47DuBY13591_at_levee.wustl.edu>

Dear Mr. Ensor:

One of the reasons that Oceanus Procellarum was
chosen as the 2nd Apollo lunar landing site,
Apollo 12, was to help answer the red-blue
question. Astronomers had noted that some of the
maria of the eastern part of the Moon were bluish
and while those on the west were reddish. (I use
east and west in the terrestrial sense, not the
astronomical sense - east is right, west is left.)

One of the surprises of Apollo 11 (Mare
Tranquillitatis) was that the basalts had very
high concentrations of titanium-bearing minerals
- ilmenite (FeO TiO2), ?lvospinel (2FeO TiO2),
and armalcolite ([Fe,Mg]O 2TiO2), a new mineral
that was named after the Apollo 11
astronauts. Ever since, the Apollo 11 basalts
have been called "high-titanium basalts" (as have
the basalts of Apollo 17, which were collected on
the edge of Mare Serenitatis, another blue area,
as you note.) The Apollo 12 basalts had much
lower concentrations of Ti. In mare
Tranquillitatis, the Ti minerals dominate the
color, making the basalts blue. At Apollo 12,
pyroxene (a Fe,Mg,Ca silicate) dominates the
color, making the basalts red. The color, thus,
is dictated by silicates and oxides of metals
(mainly Fe and Ti), not be free metal from meteorites.

Earth-based spectroscopy of the near side as well
as whole-moon spectroscopy by the Clementine
mission show that high-Ti basalts are really not
so common on the Moon. None of the basaltic
lunar meteorites are composed of the high-Ti
basalts. They're all "low-Ti basalts" or "very-low-Ti (VLT) basalts."

Sincerely,
Randy Korotev








At 10:21 05-05-07 Saturday, you wrote:
>Hi all,
>
>Not far back there was a discussion on the list
>about iron contentent in lunar
>samples/meteorites and I thought this seemed related.
>
>I have just been sent this email by a friend
>from my local astronomy society who is into
>astrophotography and wondered if any
>knowledgable people on the list would like to
>comment. I have never heard of of or seen this
>before and thought it sounded dubious. If
>anyone is interested in the photograph I could email it to you.
>
>email below...
>Last night (29-04-07) I managed to image the
>moon and process it in such a way that it
>brought out the lunar colours signifying
>different types of rock on the surface. There
>are two images attached to this email, one is an
>unprocessed one (almost "black and white" but it
>is in fact a colour image!) and the second has
>had the colour process done on it.
>The images are a stack of 31 frames taken with a
>C8-NGT/Moonlite CR-1 and a Canon EOS300D/MPCC
>combination. Each single image was at 100ASA and
>exp was 1/200th second. To achieve the colour
>processed the image was neutral colour balanced
>so that when the saturation was adjusted it
>didn't favour any one colour. Once done, the
>saturation was increased in three stages of +30
>and then in a couple stages of +10. Once the
>final colour balance was achieved, the image was
>unsharp masked and contrast adjusted to achieve the final result.
>Checking information on the internet, the
>colours signify areas of differing amounts of
>metal in the basalts on the Mare regions, the
>bluer the area the more metal, the oranger the
>area the less metal. Mare Tranquilitatis is very
>blue in comparison to neighbouring Mare
>Serenitatis although round the edge of
>Serenitatis, the metal composite is higher
>around the edge of the "shoreline" in comparison
>to the centre of the "sea." Mare Humorum (to the
>lower left) displays the opposite colourations
>to Mare Serenitatis. Sinus Iridum, on the other
>hand, is very clearly low on metals and has a
>distinct border with Oceanus Procellarum plateau
>and from the processed image Mare Frigoris, on
>the northern edge of the lunar face, is low on metal.
>
>
>Graham Ensor, nr Barwell UK
>
>______________________________________________
>Meteorite-list mailing list
>Meteorite-list at meteoritecentral.com
>http://six.pairlist.net/mailman/listinfo/meteorite-list
>

~+~+~+~+~+~+~+~+~+~+~+~+~+~+~+~+~+~+~+~+~+~+~+~+~+~+~+~+~+~+~+~+
Randy L. Korotev phone: (314) 935-5637
Research Associate Professor fax: (314) 935-7361
Washington University in Saint Louis korotev at wustl.edu
Department of Earth & Planetary Sciences http://epsc.wustl.edu/

Everything you need to know about lunar meteorites:
http://meteorites.wustl.edu/lunar/moon_meteorites.htm
Received on Mon 07 May 2007 09:56:13 AM PDT