[meteorite-list] Science Benefits from Diverse Landing Area of Curiosity Mars Rover

[Ron Baalke]

September 26, 2013

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

Guy Webster
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-6278
guy.webster at jpl.nasa.gov 
     
RELEASE 13-298
     
Science Benefits from Diverse Landing Area of NASA Mars Rover

NASA's Curiosity rover is revealing a great deal about Mars, from long-ago  
processes in its interior to the current interaction between the Martian  
surface and atmosphere.

Examination of loose rocks, sand and dust has provided new understanding of  
the local and global processes on Mars. Analysis of observations and  
measurements by the rover's science instruments during the first four months  
after the August 2012 landing are detailed in five reports in this week's  
edition of the journal Science.

A key finding is water molecules are bound to fine-grained soil particles,  
accounting for about 2 percent of the particles' weight at Gale Crater where  
Curiosity landed. This result has global implications, because these  
materials are likely distributed around the Red Planet.

Curiosity also has completed the first comprehensive mineralogical analysis  
on another planet using a standard laboratory method for identifying minerals  
on Earth. The findings about both crystalline and non-crystalline components  
in soil provide clues to the planet's volcanic history.

Information about the evolution of the Martian crust and deeper regions  
within the planet comes from Curiosity's mineralogical analysis of a  
football-size igneous rock called "Jake M." Igneous rocks form by cooling  
molten material that originated well beneath the crust. The chemical  
compositions of the rocks can be used to infer the thermal, pressure and  
chemical conditions under which they crystallized.

"No other Martian rock is so similar to terrestrial igneous rocks," said  
Edward Stolper of the California Institute of Technology, lead author of a  
report about this analysis. "This is surprising because previously studied  
igneous rocks from Mars differ substantially from terrestrial rocks and from  
Jake M."

The other four reports include analysis of the composition and formation  
process of a windblown drift of sand and dust, by David Blake of NASA's Ames  
Research Center at Moffett Field, Calif., and co-authors.

Curiosity examined this drift, called Rocknest, with five instruments,  
preforming an onboard laboratory analysis of samples scooped up from the  
Martian surface. The drift has a complex history and includes sand particles  
with local origins, as well as finer particles that sample windblown Martian  
dust distributed regionally or even globally.

The rover is equipped with a laser instrument to determine material  
compositions from some distance away. This instrument found that the  
fine-particle component in the Rocknest drift matches the composition of  
windblown dust and contains water molecules. The rover tested 139 soil  
targets at Rocknest and elsewhere during the mission's first three months and  
detected hydrogen -- interpreted as water -- every time the laser hit  
fine-particle material.

"The fine-grain component of the soil has a similar composition to the dust  
distributed all around Mars, and now we know more about its hydration and  
composition than ever before," said Pierre-Yves Meslin of the Institut de  
Recherche en Astrophysique et Planétologie in Toulouse, France, lead author  
of a report about the laser instrument results.

A laboratory inside Curiosity used X-rays to determine the composition of  
Rocknest samples. This technique, discovered in 1912, is a laboratory  
standard for mineral identification on Earth. The equipment was miniaturized  
to fit on the spacecraft that carried Curiosity to Mars, and this has yielded  
spinoff benefits for similar portable devices used on Earth. David Bish of  
Indiana University in Bloomington co-authored a report about how this  
technique was used and its results at Rocknest.

X-ray analysis not only identified 10 distinct minerals, but also found an  
unexpectedly large portion of the Rocknest composition is amorphous  
ingredients, rather than crystalline minerals. Amorphous materials, similar  
to glassy substances, are a component of some volcanic deposits on Earth.

Another laboratory instrument identified chemicals and isotopes in gases  
released by heating the Rocknest soil in a tiny oven. Isotopes are variants  
of the same element with different atomic weights. These tests found water  
makes up about 2 percent of the soil, and the water molecules are bound to  
the amorphous materials in the soil.

"The ratio of hydrogen isotopes in water released from baked samples of  
Rocknest soil indicates the water molecules attached to soil particles come  
from interaction with the modern atmosphere," said Laurie Leshin of  
Rensselaer Polytechnic Institute in Troy, N.Y., lead author of a report about  
analysis with the baking instrument.

Baking and analyzing the Rocknest sample also revealed a compound with  
chlorine and oxygen, likely chlorate or perchlorate, which previously was  
known to exist on Mars only at one high-latitude site. This finding at  
Curiosity's equatorial site suggests more global distribution.

Data obtained from Curiosity since the first four months of the rover's  
mission on Mars are still being analyzed. NASA's Jet Propulsion Laboratory in  
Pasadena, Calif., manages the mission for NASA's Science Mission Directorate  
in Washington. The mission draws upon international collaboration, including  
key instrument contributions from Canada, Spain, Russia and France.

For more information about the mission, visit:

http://www.nasa.gov/msl 

and

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

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