On August 19, 2012, NASA's Curiosity rover used the ChemCam, its laser-camera combo unit, for the first time on Mars, firing an energy beam at a small rock called "Coronation."
Having excited the atoms in a target rock into an ionized, glowing plasma with its million watt laser, ChemCam can then use its telescopic camera to watch the light emitted and analyze it with three spectrometers for information about elemental composition.
This first firing of the laser was primarily for target practice and calibration, but the ChemCam team expects to eventually take about a dozen compositional measurements of rocks per day. The spectrometers consist of three separate units covering 240 to 336 nanometer, 380 to 470 nanometer, and 470 to 850 nanometer spectral ranges, recording intensity at 6,144 different wavelengths of ultraviolet, visible, and infrared light.
"It's surprising that the data are even better than we ever had during tests on Earth, in signal-to-noise ratio," said ChemCam Deputy Project Scientist Sylvestre Maurice of the Institut de Recherche en Astrophysique et Planetologie (IRAP) in Toulouse, France. "It's so rich, we can expect great science from investigating what might be thousands of targets with ChemCam in the next two years."
ChemCam's Laser-induced breakdown spectroscopy has been used to determine composition of targets in other extreme environments, such as inside nuclear reactors and on the seafloor, and has had experimental applications in environmental monitoring and cancer detection. "Coronation" is the first rock on any extraterrestrial planet to be investigated with such a laser test.