The 100,000th "zap" was one of a series of 300 to investigate locations on a rock called "Ithaca," at a distance of 13 feet, 3 inches from the laser on the rover's mast, the space agency's Jet Propulsion Laboratory in Pasadena, Calif., said Thursday.
The rover's Chemistry and Camera instrument uses an infrared laser to turn material in a pinhead-size spot on the target into a glowing, ionized gas, called plasma, then observes that spark with a telescope and analyzes the spectrum of light to identify elements in the target.
"Passing 100,000 laser shots is terribly exciting and is providing a remarkable set of chemical data for Mars," ChemCam co-investigator Horton Newsom of the University of New Mexico, Albuquerque, said.
Virtually every shot on a target -- most of which get zapped at several points with 30 laser pulses at each point -- returns a spectrum of data to Earth.
Each pulse delivers more than a million watts of power for about one-billionths of a second, NASA said.