Econintersect: The Martian rover Curiosity has made some compositional measurements on a triangular wedge shaped rock about the size of a football. The rock is high in elements that would be found in feldspar on earth. Various classes of feldspars as a group make up as much as 60% of the earth’s crust, according to Wikipedia and crystallize from magma in both intrusive and extrusive igneous rocks, as veins, and are also present in many types of metamorphic rock. NASA has named the rock “Jake Matijevic.”
The visible markings superimposed on the picture define the test locations on the rock.
Although feldspars as a class are quite common, the composition found in the Jake rock is not common on earth. According to the NASA press release:
“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, 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.
It is interesting that water is mentioned in discussing this rock since two weeks ago other Martian water news was reported from NASA regarding the exploration of an ancient Martian stream bed.
The following picture from NASA compares photgraphs of sedimentary conglomerate formations on the two planets:
Click on image to read NASA report.
Here is the full NASA press release about the Jake rock:
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” (matt-EE-oh-vick) 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, 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 (WEENS) 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 (room-eel-ee-OH-tiss), lead turret rover planner at NASA’s Jet Propulsion Laboratory 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 and http://mars.jpl.nasa.gov/msl .
You can follow the mission on Facebook and Twitter at: http://www.facebook.com/marscuriosity and http://www.twitter.com/marscuriosity .
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Guy Webster / D.C. Agle 818-354-5011
Jet Propulsion Laboratory, Pasadena, Calif.
[email protected] / [email protected]
Dwayne Brown 202-358-1726
NASA Headquarters, Washington
[email protected]Related Video: http://mars.jpl.nasa.gov/msl/multimedia/videos/index.cfm?v=96
Sources:
- Mars Rock Touched By NASA Curiosity Has Surprises (NASA press release, 11 October 2012)
- NASA Rover Finds Old Streambed on Martian Surface (NASA press release, 27 September 2012)
- Rock Outcrops on Mars and Earth (NASA multimedia report, 26 September 2012)
