Hey, remember that one ton nuclear rover we sent to Mars? Yeah, that. On October 20, it aimed its megaWatt laser at the sand on Mars and blasted it 30 times in rapid succession, carving out a hole about 3 mm across. NASA kindly has provided a before-and-after animation of the damage inflicted on the Red Planet:
Cool, eh? [Click to coherentlightenate.]
Curiosity's laser is designed not as a weapon against a hapless Marvin, but instead to do actual science. It very rapidly heats the rock (or sand or whatever) to the point where it vaporizes. Material heated like that glows, and in fact glows at very specific colors. By identifying those colors, scientists can determine precisely what the material is composed of. I gave the details in an earlier post when Curiosity zapped its first rock. You should read it, because spectroscopy is cool, and I spent many years doing it.
This sand was chosen to get lasered because it's made of fine grains that are blown by the wind. Some Martian sand is bigger, some smaller, but it's all pretty much formed from eroded rocks. But different grains may have different compositions, and be blown around differently. The only way to know is to find out. So Curiosity will be blasting various things as it roves around Gale crater, its home for the next two years.
Curiosity's real name is Mars Science Laboratory, and it's useful to keep that in mind. It's not just some golf cart tooling around the planet; it's a fully functional science lab, with cameras, spectroscopes, sampling devices, and more. Everything it does is so we can learn more about Mars. What's the the history of the planet? Why is its geology the way it is? What's the deal with it used to having water? Where'd it all go?
I think these are questions worth exploring, even if it means blasting tiny holes in the planet to find out.
Image credit: NASA/JPL-Caltech/LANL/CNES/IRAP/LPGN/CNRS. Tip o' the Illudium Q-36 Explosive Space Modulator to Keri Bean, including the idea for the title.