Written by Guy Webster and D.C. Agle
NASA’s Jet Propulsion Laboratory
Pasadena, CA – NASA’s rover Curiosity touched a Martian rock with its robotic arm for the first time on September 22nd, assessing what chemical elements are in the rock called “Jake Matijevic.”
After a short drive the preceding day to get within arm’s reach of the football-size rock, Curiosity put its Alpha Particle X-Ray Spectrometer (APXS) instrument in contact with the rock during the rover’s 46th Martian day, or sol.
![This image combines photographs taken by the Mars Hand Lens Imager (MAHLI) at three different distances from the first Martian rock that NASA's Curiosity rover touched with its arm. (Image credit: NASA/JPL-Caltech/MSSS ) This image combines photographs taken by the Mars Hand Lens Imager (MAHLI) at three different distances from the first Martian rock that NASA's Curiosity rover touched with its arm. (Image credit: NASA/JPL-Caltech/MSSS )](https://www.clarksvilleonline.com/wp-content/uploads/2012/09/Curiosity-Finishes-Close-Inspection-of-Rock-Target-1-480x360.jpg)
The Chemistry and Camera (ChemCam) instrument, which shoots laser pulses at a target from the top of Curiosity’s mast, also assessed what chemical elements are in the rock Jake Matijevic. Using both APXS and ChemCam on this rock provides a cross calibration of the two instruments.
![This image shows the robotic arm of NASA's Mars rover Curiosity with the first rock touched by an instrument on the arm. (Image credit: NASA/JPL-Caltech) This image shows the robotic arm of NASA's Mars rover Curiosity with the first rock touched by an instrument on the arm. (Image credit: NASA/JPL-Caltech)](https://www.clarksvilleonline.com/wp-content/uploads/2012/09/Curiosity-Finishes-Close-Inspection-of-Rock-Target-2-480x360.jpg)
With a final ChemCam laser testing of the rock on Sol 48 (September 24th), Curiosity finished its work on Jake Matijevic. The rover departed the same sol, with a drive of about 138 feet (42 meters), its longest yet. Sol 48, in Mars local mean solar time at Gale Crater, ended at 3:09pm September 24th, PDT.
JPL, a division of the California Institute of Technology, Pasadena, manages the Mars Science Laboratory Project, including Curiosity, for NASA’s Science Mission Directorate, Washington, D.C. JPL designed and built the rover. The Space Division of MDA Information Systems Inc. built the robotic arm in Pasadena.
More information about Curiosity is online at http://www.nasa.gov/msl and http://mars.jpl.nasa.gov/msl/ . You can follow the mission on Facebook at: http://www.facebook.com/marscuriosity and on Twitter at: http://www.twitter.com/marscuriosity .