[meteorite-list] Japan Says Hayabusa Brought Back Asteroid Grains

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Tue, 16 Nov 2010 16:58:42 -0800 (PST)
Message-ID: <201011170058.oAH0whJM015681_at_zagami.jpl.nasa.gov>

http://www.spaceflightnow.com/news/n1011/16hayabusa/

Japan says Hayabusa brought back asteroid grains
BY STEPHEN CLARK
SPACEFLIGHT NOW
November 16, 2010

KODIAK, Alaska -- Japanese scientists have concluded the Hayabusa probe
limped back to Earth with the first flakes of an asteroid ever returned
to terrestrial labs from deep space.

Particles from one of two sample containers inside Hayabusa's return
capsule were collected from the surface of Itokawa, the potato-shaped
asteroid surveyed by the spacecraft in late 2005.

The Japan Aerospace Exploration Agency, or JAXA, publicly released the
results Tuesday in a written statement.

Analysis with a scanning electron microscope identified about 1,500
grains from one sample catcher as rocky particles, according to the JAXA
press release.

"Most of them were judged to be of extraterrestrial origin and
definitely from asteroid Itokawa," the statement said.

According to researchers, the composition of Hayabusa's samples was more
similar to primitive meteorites than known rocks from Earth. The
material matches chemical maps of Itokawa from Hayabusa's remote sensing
instruments.

JAXA found concentrations of olivine and pyroxene in the Hayabusa
samples, the agency press release said.

The particles are also different from native soils at the mission's
launch base in southern Japan and landing site in Woomera, Australia.

After Hayabusa's return to Earth in June, scientists opened up the
craft's sample container and discovered rocky grains. But confirmation
of the material's origin did not come until this week.

Officials retrieved the particles with a special spatula inside a
curation facility at Sagamihara, Japan.

Further study of the samples will wait until 2011 because officials are
still developing special handling procedures to avoid contaminating the
particles during the next phase of research.

Most of the particles are smaller than 10 micrometers.

Scientists have not analyzed samples inside the capsule's other
collection chamber, but officials expect it to hold even more material
because of its location on the spacecraft.

It lies on the side of the spacecraft that touched Itokawa with the most
force during its time at the asteroid, possibly gathering more rock grains.

Hayabusa was designed to collect several hundred milligrams of material
if the sampling procedure went as planned, but the craft's projectile
gun did not activate when it approached the asteroid.

Scientists expect to learn much about asteroids from even a miniscule
sample through powerful tools like scanning electron microscopes.
Received on Tue 16 Nov 2010 07:58:42 PM PST