When it departs for its journey to Mars later this year, NASA’s Mars 2020 rover won’t only be armed with an array of scientific instruments — it will also be toting a high-powered laser.
The laser is part of the rover’s SuperCam instrument for analyzing rocks and minerals found on the Martian surface. The laser beam sends out pulses from the end of the mast, which you could think of as the rover’s “head,” vaporizing rocks from up to 20 feet away. Once a rock is vaporized, the instrument can analyze the material to search for particular elements or chemical compounds.
The laser heats its targets to around 18,000 degrees Fahrenheit, converting solid material into plasma. This plasma is then imaged by a camera which can determine the chemical makeup of the material, in a method called laser-induced breakdown spectroscopy.
Mars 2020’s mast, or “head,” includes a laser instrument called SuperCam that can vaporize rock material and study the resulting plasma. NASA/JPL-Caltech
The engineers are particularly keen to search for minerals that form in the presence of liquid water, such as clays, carbonates, and sulfates. If there ever was life on Mars, then it would likely have been microbial life which formed near to liquid water, so the rover will be searching the site of an ancient lake for evidence of fossilized microbes.
Another use for the laser is identifying rock targets of interest for caching. The rover is armed with a rotating array of drill bits which form a carousel for collecting samples. The idea is that Mars 2020 will identify and collect samples, then leave these samples on the planet’s surface for collection by a future mission. As there are only a limited number of sample tubes, using the laser will allow the team to determine whether a given area of rock is worth sampling.
Another tool that the rover will have in its arsenal is a microphone, through which the researchers can hear the laser hitting its targets. The material that a rock is made of will affect the popping sound it makes when hit with a laser.
“The microphone serves a practical purpose by telling us something about our rock targets from a distance. But we can also use it to directly record the sound of the Martian landscape or the rover’s mast swiveling,” Sylvestre Maurice of the Institute for Research in Astrophysics and Planetary Science in Toulouse, France, explained in a statement.
The Mars 2020 mission is set to launch in July this year.