Scientists at NASA’s Jet Propulsion Laboratory in Pasadena, Calif., reported last month that the Mars rover Curiosity had fired its “100,000th laser shot as one of a series of 300 to investigate 10 locations on a rock called ‘Ithaca’ in late October.” The laser and telescope on the rover’s mast were 13 feet 3 inches (4.04 meters) away from the rock when the shot was fired.
According to the NASA website, “The Chemistry and Camera instrument (ChemCam) uses the infrared laser to excite material in a pinhead-size spot on the target into a glowing, ionized gas called plasma. ChemCam observes that spark with the telescope and analyzes the spectrum of light to identify elements in the target.”
The photograph, taken by Marc Buehler at Fermilab, shows a device known as an alpha particle X-ray spectrometer, which is not part of the ChemCam but is installed on Curiosity for a very different type of analysis. Wikipedia says the APXS “is a device that analyses the chemical element composition of a sample from the scattered alpha particles, and fluorescent X-rays after the sample is irradiated with alpha particles and X-rays from radioactive sources.”
In order to identify the composition of Mars, the ChemCam and APXS devices aboard Curiosity are helping us, along with eight other instruments on Curiosity’s science payload.
Fermilab, formally the US Department of Energy’s Fermi National Accelerator Laboratory, is located in Batavia, Ill., about 35 miles west of Chicago. See a brief description of the lab’s Top 10 discoveries in physics and energy on the smallest scale in the universe, here.
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