[meteorite-list] NRL Researchers Investigate Early Solar System

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Tue Aug 15 12:47:48 2006
Message-ID: <200608151636.JAA24395_at_zagami.jpl.nasa.gov>

http://www.nrl.navy.mil/pressRelease.php?Y=2006&R=44-06r

NRL Press Release
44-06r

NRL Researchers Investigate Early Solar System
August 14, 2006

Scientists at the Naval Research Laboratory are part of an international
research team that is studying minerals formed during the early history
of the solar system. Their goal is to learn more about the chemical and
physical processes that occurred during the formation of the solar
system. Their research was published in the May 2006 issue of
Meteoritics and Planetary Science where a figure from the paper was
selected as the cover image.

The researchers studied serpentine minerals in a group of primitive
meteorites called CM carbonaceous chondrites. The CM carbonaceous
chondrites formed over 4.5 billion years ago in the solar nebula, the
cloud of gas and dust from which our sun and planets formed.

Using a transmission electron microscope (TEM), the researchers imaged
the three-dimensional structure of the serpentines and analyzed their
compositions. A TEM is capable of imaging the atomic structure of a
material, and the research team needed its resolving power to analyze
the serpentines, which are small, on the order of 90 nanometers (1
nanometer = 0.000000001 meter).

Serpentines form by chemical reaction of anhydrous silicates (minerals
that do not contain hydrogen) and water. The research team's findings
reveal that the formation of these minerals occurred under oxygen-rich
conditions, and suggest that the parent asteroids of the meteorites
contained active hydrothermal systems that were capable of driving
chemical reactions. Such reactions were likely similar to those that
occur on Earth, but transpired over 4.5 billion years ago in space.

Thomas Zega, who is the lead author on the paper, and Rhonda Stroud are
researchers in NRL's Materials Science and Technology Division. The
research team also includes members from Arizona State University,
E?tv?s L. University in Budapest, Hungary, and Utrecht University in The
Netherlands.


[image]
A 3-D tomographic reconstruction of a ~90-nm wide polyhedral serpentine
grain from the Mighei CM carbonaceous chondrite meteorite. The surface
of the tomogram is made semitransparent to visualize the interior. At
the core is an elongated structure that extends the length of the grain.
When viewed in axial orientation this structure is hollow from one end
to the other, indicating that it is tubular. The tomogram was
reconstructed from 120 bright-field images acquired over a tilt range of
+/- 60 degrees.


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Received on Tue 15 Aug 2006 12:36:21 PM PDT