There are several types of spectrometers:
The near-infrared mapping spectrometer will map a planet or moon, looking for different minerals across its surface. It will also study cloud structure and gas composition in the atmosphere around the planet or moon.
An ultraviolet spectrometer and extreme ultraviolet spectrometer will study the materials of which a planet or moon is made, certain physical properties of its clouds, and the composition, structure, and evolution of the planet or moon's upper atmosphere.