NASA’s Mars rover Curiosity fired its laser for the first time on Mars, using the beam from a science instrument to interrogate a fist-size rock called “Coronation.” The mission’s Chemistry and Camera instrument, or 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.