Rover’s laser instrument zaps first martian rock

The energy from the laser excites atoms in the rock into an ionized, glowing plasma, and then Curiosity’s ChemCam analyzes it for element information.
By | Published: August 20, 2012 | Last updated on May 18, 2023
This composite image, with magnified insets, depicts the first laser test by the ChemCam instrument aboard NASA’s Curiosity Mars rover. // Image credit: NASA/JPL-Caltech/LANL/CNES/IRAP
Yesterday, the Mars rover Curiosity fired its laser for the first time on the Red Planet, using the beam from a science instrument to zap a fist-sized rock called “Coronation.”

The mission’s Chemistry and Camera instrument (ChemCam) hit the fist-sized rock with 30 pulses of its laser during a 10-second period. Each pulse delivers more than a million watts of power for about five one-billionths of a second.

The energy from the laser excites atoms in the rock into an ionized, glowing plasma. ChemCam catches the light from that spark with a telescope and analyzes it with three spectrometers for information about what elements are in the target.

“We got a great spectrum of Coronation — lots of signal,” said Roger Wiens of Los Alamos National Laboratory in New Mexico. “Our team is both thrilled and working hard, looking at the results. After eight years building the instrument, it’s payoff time!”

ChemCam recorded spectra from the laser-induced spark at each of the 30 pulses. The goal of this initial use of the laser on Mars was to serve as target practice for characterizing the instrument, but the activity may provide additional value. Researchers will check whether the composition changed as the pulses progressed. If it did change, that could indicate dust or other surface material being penetrated to reveal different composition beneath the surface. The spectrometers record 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 Sylvestre Maurice of the Institute of Research in Astrophysics and Planetary Science 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.”

The technique used by ChemCam, called laser-induced-breakdown spectroscopy, has been used to determine composition of targets in other extreme environments, such as inside nuclear reactors and on the sea floor, and has had experimental applications in environmental monitoring and cancer detection. Yesterday’s investigation of Coronation was the first use of the technique in interplanetary exploration.

Curiosity landed on Mars two weeks ago, beginning a two-year mission using 10 instruments to assess whether a carefully chosen study area inside Gale Crater has ever offered environmental conditions favorable for microbial life.