This is a rock. It’s been given the seemingly arbitrary name of N165. Which, as I’m sure you can guess, means it’s no ordinary piece of basalt.
This rock is special because it’s on Mars, and it’s set to be the test subject for Curiosity’s ChemCam instrument. If you don’t know what ChemCam is, it’s probably because most people don’t use the name. They just refer to it as “that laser”.
ChemCam is possibly the coolest instrument any space vehicle’s been equipped with. And not just because it uses a laser. What ChemCam does is to hit its target with a sharp series of laser pulses – 30 per second, which is about the same as the frame rate of most television sets. Those laser blasts vapourise some of the target into plasma, and a small telescope takes a spectrum of that plasma and uses it to determine the composition of whatever the target was.
In this case, they’re not expecting anything interesting. N165 is just a fairly mundane piece of basalt, not unlike every other piece on Mars. Nor is it unlike most of the basalt on Earth, for that matter. But then, this rock wasn’t chosen because it’s interesting. Oh no. It’s a test rock. And test specimens like this are best if they’re as boring as can be!
I can’t help but wonder if something similar to ChemCam may be used by any prospecting craft which those asteroid miners may eventually send out…