[meteorite-list] Aluminum-Bearing Site on Mars Draws NASA Visitor (Opportunity)

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Tue, 24 Jun 2014 10:50:20 -0700 (PDT)
Message-ID: <201406241750.s5OHoKjI012509_at_zagami.jpl.nasa.gov>

http://www.jpl.nasa.gov/news/news.php?release=2014-201

Aluminum-Bearing Site on Mars Draws NASA Visitor
Jet Propulsion Laboratory
June 24, 2014

With its solar panels their cleanest in years, NASA's decade-old Mars
Exploration Rover Opportunity is inspecting a section of crater-rim
ridgeline chosen as a priority target due to evidence of a water-related
mineral.

Orbital observations of the site by another NASA spacecraft, Mars
Reconnaissance Orbiter, found a spectrum with the signature of aluminum
bound to oxygen and hydrogen. Researchers regard that signature as a
marker for a mineral called montmorillonite, which is in a class of clay
minerals called smectites. Montmorillonite forms when basalt is altered
under wet and slightly acidic conditions. The exposure of it extends
about 800 feet (about 240 meters) north to south on the western rim of
Endeavour Crater, as mapped by the orbiter's Compact Reconnaissance
Imaging Spectrometer for Mars (CRISM).

"It's like a mineral beacon visible from orbit saying, 'Come check this
out,'" said Opportunity Principal Investigator Steve Squyres, of Cornell
University, Ithaca, New York.

Some of the most important findings from Opportunity's long mission came
from combining CRISM and rover observations of a site about 2 miles (3
kilometers) farther north on the crater's western rim. Rocks exposed
there contain evidence for an iron-bearing smectite - called nontronite
-- as well as for montmorillonite. That site yielded evidence for an
ancient environment with water that would have been well-suited for use
by microbes, if Mars had any billions of years ago.

Evidence that Opportunity may add about the geological context for
different smectites could boost understanding about diversity and
changes in ancient wet environments on Mars.

Opportunity reached the northern end of the montmorillonite-bearing
exposure last month, at a high spot called "Pillinger Point."
Opportunity's international science team chose that informal name in
honor of Colin Pillinger (1943-2014). Pillinger was the British
principal investigator for the Beagle 2 project, which attempted to set
a research lander on Mars a few weeks before Opportunity's January 2004
landing.

"Colin and his team were trying to get to Mars at the same time that we
were, and in some ways they faced even greater challenges than we did,"
Squyres said. "Our team has always had enormous respect for the energy
and enthusiasm with which Colin Pillinger undertook the Beagle 2
mission. He will be missed."

Though selected as a science destination, Pillinger Point also offers a
scenic vista from atop the western rim of Endeavour Crater, which is
about 14 miles (22 kilometers) in diameter.

A color view of Pillinger Point from the rover's panoramic camera
(Pancam) is available at:

http://www.nasa.gov/jpl/mer/pia18393

Initial measurements at this site with the element-identifying alpha
particle X-ray spectrometer at the end of Opportunity's arm indicate
that bright-toned veins in the rock contain calcium sulfate. Scientists
deduce this mineral was deposited as water moved through fractures on
Endeavour's rim. The rover earlier found veins of calcium sulfate
farther north along the rim.

As Opportunity investigates this site and sites farther south along the
rim, the rover has more energy than usual.

"The solar panels have not been this clean since the first year of the
mission," said Opportunity Project Manager John Callas of NASA's Jet
Propulsion Laboratory, Pasadena, California. "It's amazing, when you
consider that accumulation of dust on the solar panels was originally
expected to cause the end of the mission in less than a year. Now it's
as if we'd been a ship out at sea for 10 years and just picked up new
provisions at a port of call, topping off our supplies."

Both Opportunity and its rover twin, Spirit, benefited from sporadic
dust-cleaning events in past years. However, on the ridge that
Opportunity has been navigating since late 2013, winds have removed dust
more steadily, day by day, than either rover has experienced elsewhere.

"It's easy to forget that Opportunity is in the middle of a Martian
winter right now," said JPL's Jennifer Herman, power-subsystem engineer.
"Because of the clean solar arrays, clear skies and favorable tilt,
there is more energy for operations now than there was any time during
the previous three Martian summers. Opportunity is now able to pull
scientific all-nighters for three nights in a row -- something she
hasn't had the energy to do in years."

The rover's signs of aging -- including a stiff shoulder joint and
occasional amnesia events -- have not grown more troublesome in the past
year, and no new symptoms have appeared.

During Opportunity's first decade on Mars and the 2004-2010 career of
Spirit, NASA's Mars Exploration Rover Project yielded a range of
findings about wet environmental conditions on ancient Mars -- some very
acidic, others milder and more conducive to supporting life.

JPL manages the Mars Exploration Rover Project for NASA's Science
Mission Directorate in Washington. The California Institute of
Technology in Pasadena manages JPL for NASA.

For more information about Spirit and Opportunity, visit:

http://www.nasa.gov/rovers

http://marsrovers.jpl.nasa.gov

You can follow the project on Twitter and on Facebook at:

http://twitter.com/MarsRovers

http://www.facebook.com/mars.rovers

Guy Webster 818-354-6278
Jet Propulsion Laboratory, Pasadena, Calif.
guy.webster at jpl.nasa.gov

2014-201
Received on Tue 24 Jun 2014 01:50:20 PM PDT