|Image credit: NASA/JPL-Caltech/MSSS|
'Jake Matijevic', the first Martian rock the 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 the Earth's interior.
This image shows red dots are where the Chemistry and Camera (ChemCam) instrument zapped it with its laser on Sept. 21, 2012, and Sept. 24, 2012, which were the 45th and 48th sol, or Martian day of operations. The circular black and white images were taken by ChemCam to look for the pits produced by the laser. The purple circles indicate where the Alpha Particle X-ray Spectrometer trained its view.
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. Edward Stolper of the California Institute of Technology said, "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. 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.
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.
The pyramid shaped rock was named in memory of Jacob Matijevic (1947-2012), the surface operations systems chief engineer for the Mars Science Laboratory Project who played a critical role in the design of the six-wheeled rover. (See The Story of Jake and a Rock on Mars )