SPECTROSCOPY

About:

• Spectroscopy is the technique of splitting light (or more precisely electromagnetic radiation) into its constituent wavelengths (a spectrum), in much the same way as a prism splits light into a rainbow of colours.
  
  
• Old style spectroscopy was carried out using a prism and photographic plates. These days, modern spectroscopy uses diffraction gratings to disperse the light, which is then projected onto CCDs (Charge Coupled Devices) similar to those used in digital cameras.
  
  

Imaging Infrared Spectrometer (IIRS):

• IIRS is designed to measure light from the lunar surface in narrow spectral channels (bands). It has the ability to split and disperse reflected sunlight (and its emitted component) into these spectral bands.
  
  
• From the reflected solar spectrum, scientists will look for signatures, including of minerals. This will help map the lunar surface composition, which in turn will help us understand the Moon’s origin and evolution in a geologic context.