The best way to figure out what something's made of? Vaporise it. With a laser. That's NASA's philosophy, anyway, in the form of a high-energy laser system that's going to be mounted on the next Mars rover. PEWPEW.
The laser-induced breakdown spectroscopy system (LIBS), called ChemCam, will launch next year on the Mars Curiosity. It sends an average of three 10-watt, five-nanosecond laser pulses per second, which may not be enough to stun a Romulan but is perfect for collecting and analysing rock samples:
The laser shots vaporize a crater less than a millimeter across, turning its molecules into a 14,000-degree plasma. The atoms are shorn of their electrons, but as the plasma ball cools down, they return to a more normal state. The electrons drop into their orbits around the nucleus and as they do so, the little plasma ball emits light...
The specific colour of the light tells scientists exactly what element they are looking at if they pass it through a spectrometer, which can precisely measure the wavelength of light.
The technique could be equally handy right here on earth for forensics experts to examine crime scenes. Or, more likely, for evil genius supervillains to create them. [Wired]