File:KSC-05-S-00255 (ksc 080805 mro smrekar6).webm

English: Our next question comes from Palak from Chicago. How will the Mars Reconnaissance Orbiter find out about the ground's chemical components from orbit? Okay. Well, we have a spectrometer onboard, and as the name implies, it uses the spectrum of light to look at the surface in a range of wavelengths. You've probably seen light go through a prism and split into a range of colors.The spectrum of light in the visible wavelength actually has a whole bunch of different colors at different wavelengths. So, as light strikes the surface, depending on how that light interacts with the surface, some of it will be absorbed in one color or reflected in another color, and that tells us what the color is. Similarly, a spectrometer looks at a different part of the spectrum, not the visible part but a different part, and it looks at the spectrum that's returned. So, given mineral, you know, like quartz and calcite, they look the same, they're white, it's a little bit hard to tell them apart, but with the spectrometer, as they look at it in a different part of the wavelength, different parts on the surface, the different elements and atoms in that, in that mineral, will cause the spectrum to have a different appearance. It'll, it'll be absorbed in one part and reflected in another part. So each mineral has its own unique signature that we can see from using the spectrometer onboard.