[meteorite-list] Martian Meteorite May Contain Water (NWA 817 )

From: Robert Verish <bolidechaser_at_meteoritecentral.com>
Date: Thu Apr 22 09:44:12 2004
Message-ID: <20010614230901.93690.qmail_at_web10404.mail.yahoo.com>

--- "Treiman, Allan" <Treiman_at_lpi.usra.edu> wrote:
> Hi -
> This report of martian water in the new nakhlite
> is interesting but not surprising.

Not only is this "not surprising", this isn't even
news-worthy. Most Mars-rock meteorites have evidence
of water (in some chemical state), even Los Angeles.

I hate to throw cold (terrestrial) water on this
discussion, but this press release raises more
questions than it answers. Much like the previous
press release about the Italian claim of resuscitating
Martian microbes, these results from the French
researchers may require some peer review.

(Speaking of peer review, most researchers that I have
spoken with, suspect terrestrial contamination.)

What would really help in our discussion would be to
know - in what chemical form is this "water" in NWA
817 - or stated differently, in what mineral phase
were the deuterium-hydrogen measurements taken. For
instance, in LA 001 the deuterium-hydrogen
measurements were taken from a mineral phase known as
apatite, a HYDROUS phosphate. The "water" that formed
this mineral came from deep within Mars, but most
geologists wouldn't call it's physical state a "fluid"
as the French team has.

No eyebrows were raised when the results of tests on
LA 001 were returned and showed that the isotope
ratios were different from what was expected of
Martian "atmospheric" ratios. These results from LA
001 were simply explained as being typical of isotopes
derived from "Martian mantle gases". The general
consensus of the researchers was, "ho-hum". Had the
isotope ratios been typical of the Martian atmosphere
and pre-terrestrial weathering, THEN it would have
been more news-worthy.

Most of the above information has come to me by way of
personal communication with Everett Gibson
<everett.k.gibson1_at_jsc.nasa.gov>. The last time we
communicated this is some of what he had to say:

"Age dating and exposure age information was obtained
by Larry Nyquist (JSC) and Don Bogard (JSC). Bogard
did not find any Martian atmospheric gases (Ne, Ar,
Kr, and Xe isotopic ratios similar to Viking's
atmospheric measurements) in his sample, BUT because
his sample did not contain any melt glass from the
impact, the sample was not expected to have Martian
atmospheric gases in it. The gases were typical
Martian mantle gases.
"The second large portion of the ASU sample was sent
to Colin Pillinger of the Open University, Milton
Keynes, England. Colin measured the oxygen isotopic
compositions. The oxygen composition fits in the
center of the SNC meteorite field. Hence, further
proof the sample is similar to other SNC meteorites.
The remainder of the sample was used for nitrogen and
carbon isotopic measurements. The nitrogen work
showed the sample did not contain nitrogen 15/nitrogen
14 ratios similar to Martian atmosphere but nitrogen
compositions similar to Martian mantle compositions.
Further proof that Bogards noble gas measurements tell
the same story."


--- "Treiman, Allan" <Treiman_at_lpi.usra.edu> wrote:
> Hi -
> This report of martian water in the new nakhlite
is interesting but
> not surprising. The other three nakhlite meteorites
> contain water-bearing clay and salt minerals (like
gypsum) in
> veinlets, and the veinlets are melted when they hit
the fusion crust.
> So, the water-bearing minerals are pre-terrestrial
== martian!
>
> I wonder, though. Could NWA 817 actually be only
a piece of Nakhla?
>
> Allan
>
> Allan H. Treiman
> Lunar and Planetary Institute
> 3600 Bay Area Boulevard
> Houston, TX 77058-1113
>
> 281-486-2117
> 281-486-2162 FAX
> treiman_at_lpi.usra.edu
>
> > -----Original Message-----
> > From: Ron Baalke [SMTP:baalke_at_zagami.jpl.nasa.gov]
> > Sent: Thursday, June 14, 2001 10:54 AM
> >
> > Subject: [meteorite-list] Martian Meteorite May
Contain Water (NWA 817)
> >
>
http://news.bbc.co.uk/hi/english/sci/tech/newsid_1387000/1387399.stm
> >
> > Martian meteorite may contain water
> > Dr. David Whitehouse
> > BBC News
> > June 13, 2001
> >
> > A meteorite found in the Western Sahara may
contain water that could have
> > come from below the surface of Mars, French
researchers say.
> >
> > Discovered last December, meteorite NWA 817 weighs
104 grammes (three and
> > a half ounces).
> >
> > It is the fourth Martian meteorite to be
classified as a nakhlite because of
> > its distinctive mineral composition.
> >
> > A detailed analysis of various forms of hydrogen
within the rock suggests it
> > was exposed to water from below the surface of
Mars.
> >
> > Possible contamination
> >
> > The ratio of hydrogen and its isotope deuterium -
another form of the atom -
> > can tell researchers if the rock was exposed to
water and, possibly, where
> > that water came from.
> >
> > "We detected a very low deuterium/hydrogen ratio,
close to a reading for the
> > Earth," said Dr Phillipe Gillet, director of the
National Institute for
> > Sciences of the Universe in France.
> >
> > "Our interpretation is that this refers to a fluid
that came from the
> > planet's interior, not its surface," he added.
> >
> > Analysis of the three other known nakhlites shows
that they have also been
> > exposed to water, but which came from the planet's
surface. However, experts
> > are concerned that the water could be just the
result of contamination after
> > the Martian rock landed on Earth.
> >
> > Life questions
> >
> > Dr Monica Grady of the Natural History Museum in
London, UK, told BBC News
> > Online: "Desert meteorites are often badly
weathered, and water exchanges
> > very easily during weathering so it could be
contamination."
> >
> > Dr Gillet admits that contamination is a
possibility.
> >
> > "However, if we are right, that means part of the
water contained in the
> > Martian mantle did not rise to the surface of the
planet," he said.
> >
> > If it is confirmed that the water came from
sub-surface rocks in Mars'
> > mantle it would add to the debate about how much
water Mars had in the past.
> > Also, because life needs water, it would be
pertinent to the question of
> > life on the planet.
> >
> > Last year, the Mars Global Surveyor spacecraft in
orbit around the planet
> > saw what might be evidence of recent running water
on its surface.
> >
> > Martian meteorites are believed to have been
blasted off the planet by an
> > impact with a large object many millions of years
ago. After wandering in
> > space for millions of years some of the chunks of
rock fell down on to Earth.
> >
> > _______________________________________________



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Received on Thu 14 Jun 2001 07:09:01 PM PDT