The mars rover does have a spectrometer. It's called ChemCam [1], it uses a laser to vaporize a small amount of matter and them captures the spectrographs of th

The mars rover does have a spectrometer. It's called ChemCam [1], it uses a laser to vaporize a small amount of matter and them captures the spectrographs of the resulting plasma with a camera. That doesn't take away from your point, but it is a cool piece of equipment. [1] https://mars.nasa.gov/msl/spacecraft/instruments/chemcam/ https://mars.nasa.gov/msl/spacecraft/instruments/chemcam/