Explanation: SpeX is a medium-resolution 0.7-5.3 micron spectrograph built at the Institute for Astronomy (IfA), for the NASA Infrared Telescope Facility (IRTF) on Mauna Kea. Infrared spectroscopy is a powerful tool for probing Pluto's surface ices, since different ice species each have characteristic patterns of spectral absorption.


Image credit: NASA Infrared Telescope Facility/Institute for Astronomy, University of Hawaii.