The Mars Exploration Rover mission makes use of three spectrometers:

	Miniature Thermal Emission Spectrometer (Mini-TES) [More] --[More] should link to mission/spacecraft/rover/instruments (which doesn't exist yet, and have technical description that is currently at technology/instruments This instrument operates in the infrared part of the spectrum to identify minerals present in the rocks and soil. It can also collect data on the temperatures of rocks and soils, as well as the temperatures of a low-altitude part of the Martian atmosphere that is not yet well understood. These studies will help us learn about the past and present geology and climate of Mars.
	Mossbauer Spectrometer [More] This instrument operates in the gamma ray part of the spectrum to detect iron-bearing minerals in rocks and soils. Understanding the amount of iron in rocks and soils will help scientists understand XXXXXXX.
	Alpha Particle X-Ray Spectrometer (APXS) [More] This spectrometer operates in the X-ray part of the spectrum and uses alpha particles to determine what chemical elements (e.g., sodium, magnesium, aluminum and phosporous) are present in rocks and soil.

Miniature Thermal Emission Spectrometer (Mini-TES) is a spectrometer for remote investigation of mineralogy of rocks and soils. It operates in the thermal infrared region of the spectrum. It will identify rock-forming minerals, and also provide some capability to see through dust coatings that could tend to obscure spectral features of rocks. The mineralogical information that Mini-TES provides will be used to select from a distance the rocks and soils that will be investigated in more detail. Along with its mineralogical capabilities, Mini-TES can collect data on the thermal properties of rocks and soils. Viewing upward, it can also provide temperature profiles through the Martian atmospheric boundary layer - the layer of atmosphere from the surface to an altitude of 10 kilometers, and one that cannot be well understood from orbital instruments alone.

Mössbauer Spectrometer, mounted on the instrument arm, will specifically provide the detailed mineralogy of different kinds of iron-bearing rocks and soils. Placed directly up against target material, the spectrometer illuminates rock surfaces with gamma particles emitted by cobalt-57. The particles interact with the nuclei of the atoms in the targeted material, and characteristics of the radiation reflected back, or "backscattered," into the spectrometer are recorded and measured to determine the presence, amount and types of iron-bearing minerals. One Mössbauer measurement takes approximately 12 hours, depending on the sample's total iron content and the various types of iron-bearing minerals present. the Mössbauer spectrometer and microscopic imager, the APXS will be able to analyze the samples collected by the a small magnet array that will attract magnetic particles that settle from the Martian atmosphere.

Alpha Particle X-Ray Spectrometer (APXS)

The Alpha Particle X-ray Spectrometer, mounted on the instrument arm, works by exposing Martian materials to energetic alpha particles and X-rays from curium-244, and then measuring the energy spectra of backscattered alpha and X-radiation. The instrument is conceptually similar to but an updated and more capable version of the APXS instrument that was used on the Mars Pathfinder Sojourner rover.