[meteorite-list] NASA's Curiosity Mars Rover Finds Mineral Match

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Wed, 5 Nov 2014 14:58:05 -0800 (PST)
Message-ID: <201411052258.sA5Mw5QU011371_at_zagami.jpl.nasa.gov>

http://www.jpl.nasa.gov/news/news.php?feature=4361

NASA's Curiosity Mars Rover Finds Mineral Match
Jet Propulsion Laboratory
November 4, 2014

Reddish rock powder from the first hole drilled into a Martian mountain
by NASA's Curiosity rover has yielded the mission's first confirmation
of a mineral mapped from orbit.

"This connects us with the mineral identifications from orbit, which can
now help guide our investigations as we climb the slope and test
hypotheses derived from the orbital mapping," said Curiosity Project
Scientist John Grotzinger, of the California Institute of Technology in
Pasadena.

Curiosity collected the powder by drilling into a rock outcrop at the
base of Mount Sharp in late September. The robotic arm delivered a pinch
of the sample to the Chemistry and Mineralogy (CheMin) instrument inside
the rover. This sample, from a target called "Confidence Hills" within
the "Pahrump Hills" outcrop, contained much more hematite than any rock
or soil sample previously analyzed by CheMin during the two-year-old
mission. Hematite is an iron-oxide mineral that gives clues about
ancient environmental conditions from when it formed.

In observations reported in 2010, before selection of Curiosity's
landing site, a mineral-mapping instrument on NASA's Mars Reconnaissance
Orbiter provided evidence of hematite in the geological unit that
includes the Pahrump Hills outcrop. The landing site is inside Gale
Crater, an impact basin about 96 miles (154 kilometers) in diameter with
the layered Mount Sharp rising about three miles (five kilometers) high
in the center.

"We've reached the part of the crater where we have the mineralogical
information that was important in selection of Gale Crater as the
landing site," said Ralph Milliken of Brown University, Providence,
Rhode Island. He is a member of Curiosity's science team and was lead
author of that 2010 report in Geophysical Research Letters identifying
minerals based on observations of lower Mount Sharp by the orbiter's
Compact Reconnaissance Imaging Spectrometer for Mars (CRISM). "We're now
on a path where the orbital data can help us predict what minerals we'll
find and make good choices about where to drill. Analyses like these
will help us place rover-scale observations into the broader geologic
history of Gale that we see from orbital data."

Much of Curiosity's first year on Mars was spent investigating outcrops
in a low area of Gale Crater called "Yellowknife Bay," near the spot
where the rover landed. The rover found an ancient lakebed. Rocks there
held evidence of wet environmental conditions billions of years ago that
offered ingredients and an energy source favorable for microbial life,
if Mars ever had microbes. Clay minerals of interest in those rocks at
Yellowknife Bay had not been detected from orbit, possibly due to dust
coatings that interfere with CRISM's view of them.

The rover spent much of the mission's second year driving from
Yellowknife Bay to the base of Mount Sharp. The hematite found in the
first sample from the mountain tells about environmental conditions
different from the conditions recorded in the rocks of Yellowknife Bay.
The rock material interacted with water and atmosphere to become more
oxidized.

The rocks analyzed earlier also contain iron-oxide minerals, mostly
magnetite. One way to form hematite is to put magnetite in oxidizing
conditions. The latest sample has about eight percent hematite and four
percent magnetite. The drilled rocks at Yellowknife Bay and on the way
to Mount Sharp contain at most about one percent hematite and much
higher amounts of magnetite.

"There's more oxidation involved in the new sample," said CheMin Deputy
Principal Investigator David Vaniman of the Planetary Science Institute
in Tucson, Arizona.

The sample is only partially oxidized, and preservation of magnetite and
olivine indicates a gradient of oxidation levels. That gradient could
have provided a chemical energy source for microbes.

The Pahrump HIlls outcrop includes multiple layers uphill from its
lowest layer, where the Confidence Hills sample was drilled. The layers
vary in texture and may also vary in concentrations of hematite and
other minerals. The rover team is now using Curiosity to survey the
outcrop and assess possible targets for close inspection and drilling.

The mission may spend weeks to months at Pahrump Hills before proceeding
farther up the stack of geological layers forming Mount Sharp. Those
higher layers include an erosion-resistant band of rock higher on Mount
Sharp with such a strong orbital signature of hematite, it is called
"Hematite Ridge." The target drilled at Pahrump Hills is much softer and
more deeply eroded than Hematite Ridge.

Another NASA Mars rover, Opportunity, made a key discovery of
hematite-rich spherules on a different part of Mars in 2004. That
finding was important as evidence of a water-soaked history that
produced those mineral concretions. The form of hematite at Pahrump
Hills is different and is most important as a clue about oxidation
conditions. Plenty of other evidence in Gale Crater has testified to the
ancient presence of water.

NASA's Jet Propulsion Laboratory, a division of Caltech in Pasadena,
manages the Mars Reconnaissance Orbiter and Mars Science Laboratory
projects for NASA's Science Mission Directorate in Washington, and built
the Curiosity rover. NASA's Ames Research Center, Moffett Field,
California, developed CheMin and manages instrument operations. The
Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland,
developed and operates CRISM. For more information about Curiosity, visit:

http://www.nasa.gov/msl

http://mars.jpl.nasa.gov/msl/

You can follow the mission on Facebook and Twitter at:

http://www.facebook.com/marscuriosity

http://www.twitter.com/marscuriosity

Media Contact

Preston Dyches / Guy Webster
Jet Propulsion Laboratory, Pasadena, California
818-354-7013 / 818-354-6278
preston.dyches at jpl.nasa.gov / guy.webster at jpl.nasa.gov

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

Jessica Culler
Ames Research Center, Moffett Field, California
650-604-4789
jessica.culler at nasa.gov

Kevin Stacey
Brown University
401-863-3766
kevin_stacey at brown.edu

2014-380
Received on Wed 05 Nov 2014 05:58:05 PM PST