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

From: Treiman, Allan <Treiman_at_meteoritecentral.com>
Date: Thu Apr 22 09:44:12 2004
Message-ID: <D144DC845882D311959900500424D7D0B1BD89_at_cassnt2>

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
> To: meteorite-list_at_meteoritecentral.com
> 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 12:13:10 PM PDT