[meteorite-list] Mars Rock Touched By NASA Curiosity Rover Offers Surprises

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu, 11 Oct 2012 13:15:47 -0700 (PDT)
Message-ID: <201210112015.q9BKFlJC002371_at_zagami.jpl.nasa.gov>

Oct. 11, 2012

Dwayne Brown
Headquarters, Washington
202-358-1726
dwayne.c.brown at nasa.gov

Guy Webster / D.C. Agle
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-5011
guy.webster at jpl.nasa.gov
agle at jpl.nasa.gov


RELEASE: 12-359

MARS ROCK TOUCHED BY NASA CURIOSITY ROVER OFFERS SURPRISES

PASADENA, Calif. -- The first Martian rock NASA's Curiosity rover has
reached out to touch presents a more varied composition than expected
from previous missions. The rock also resembles some unusual rocks
from Earth's interior.

The rover team used two instruments on Curiosity to study the chemical
makeup of the football-size rock called "Jake Matijevic." The results
support some surprising recent measurements and provide an example of
why identifying rocks' composition is such a major emphasis of the
mission. Rock compositions tell stories about unseen environments and
planetary processes.

"This rock is a close match in chemical composition to an unusual but
well-known type of igneous rock found in many volcanic provinces on
Earth," said Edward Stolper of the California Institute of Technology
in Pasadena, Calif., who is a Curiosity co-investigator. "With only
one Martian rock of this type, it is difficult to know whether the
same processes were involved, but it is a reasonable place to start
thinking about its origin."

On Earth, rocks with composition like the Jake rock typically come
from processes in the planet's mantle beneath the crust, from
crystallization of relatively water-rich magma at elevated pressure.

Jake was the first rock analyzed by the rover's arm-mounted Alpha
Particle X-Ray Spectrometer (APXS) instrument and about the thirtieth
rock examined by the Chemistry and Camera (ChemCam) instrument. Two
penny-size spots on Jake were analyzed Sept. 22 by the rover's
improved and faster version of earlier APXS devices on all previous
Mars rovers, which have examined hundreds of rocks. That information
has provided scientists a library of comparisons for what Curiosity
sees.

"Jake is kind of an odd Martian rock," said APXS Principal
Investigator Ralf Gellert of the University of Guelph in Ontario,
Canada. "It's high in elements consistent with the mineral feldspar,
and low in magnesium and iron."

ChemCam found unique compositions at each of 14 target points on the
rock, hitting different mineral grains within it.

"ChemCam had been seeing compositions suggestive of feldspar since
August, and we're getting closer to confirming that now with APXS
data, although there are additional tests to be done," said ChemCam
Principal Investigator Roger Wiens of Los Alamos National Laboratory
in New Mexico.

Examination of Jake included the first comparison on Mars between APXS
results and results from checking the same rock with ChemCam, which
shoots laser pulses from the top of the rover's mast.

The wealth of information from the two instruments checking chemical
elements in the same rock is just a preview. Curiosity also carries
analytical laboratories inside the rover to provide other composition
information about powder samples from rocks and soil. The mission is
progressing toward getting the first soil sample into those
analytical instruments during a "sol" or Martian day.

"Yestersol, we used Curiosity's first perfectly scooped sample for
cleaning the interior surfaces of our 150-micron sample-processing
chambers. It's our version of a Martian carwash," said Chris
Roumeliotis, lead turret rover planner at NASA's Jet Propulsion
Laboratory (JPL) in Pasadena, Calif.

Before proceeding, the team carefully studied the material for
scooping at a sandy patch called "Rocknest," where Curiosity is
spending about three weeks.

"That first sample was perfect, just the right particle-size
distribution," said JPL's Luther Beegle, Curiosity sampling-system
scientist. "We had a lot of steps to be sure it was safe to go
through with the scooping and cleaning."

Following the work at Rocknest, the rover team plans to drive
Curiosity about 100 yards eastward and select a rock in that area as
the first target for using the drill.

During a two-year prime mission, researchers will use Curiosity's 10
instruments to assess whether the study area ever has offered
environmental conditions favorable for microbial life. JPL, a
division of Caltech, manages the project and built Curiosity. For
more about the Mars Science Laboratory Curiosity rover mission,
visit:

http://www.nasa.gov/msl

You can follow the mission on Facebook and Twitter at:

http://www.facebook.com/marscuriosity

and

http://www.twitter.com/marscuriosity

-end-
Received on Thu 11 Oct 2012 04:15:47 PM PDT