ISR-2: SPACE AND REMOTE SENSING

Exploring Mars with Curiosity and the ChemCam Instrument Suite

Abstract: 

For the last four years, NASA's Curiosity rover has been exploring Gale crater, located near the equator of Mars, discovering that it was once a large and long-lasting lake. The ChemCam instrument suite, developed at and operated from LANL, provides elemental composition measurements using laser-induced breakdown spectroscopy (LIBS). In this technique an 11 mJ pulsed laser beam is focused to < 0.5 mm diameter on rock and soil targets within 7 meters of the rover to produce optically bright plasmas. The atomic emission spectrum is collected from each laser pulse, and calibration of the spectra provides quantitative elemental abundances. So far we have returned > 400,000 spectra from the red planet. With these we have discovered unexpectedly alkali-rich igneous rocks that, along with orbital data, may indicate Mars has a lower-density continent-like crust in its southern hemisphere in spite of Mars' apparent lack of plate tectonics. We have also characterized Gale crater's sedimentary strata to understand more about the transformation of Mars' climate from a warm and wet environment to the cold and dry planet that it is now. Recent discoveries include enrichments of NaCl and boron as the rover climbs to higher (and hence more recent) layers deposited near the end of the lake's existence.