A major set of telescopes on the Cassini spacecraft designed to measure both extreme ultraviolet and far-ultraviolet light reflected or emitted from atmospheres, rings, and surfaces. Together the two instruments cover wavelengths from 55.8 to 190 nanometres and can determine the compositions, distribution, aerosol content, and temperatures of Saturn and Titan. Built by the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder, UVIS revealed that there is more ice toward the outer part of Saturn’s rings than the inner part and that Saturn’s auroras are like Earth’s aurorae; it also detected methane lakes on Titan, hot water plumes squirting from the moon Enceladus, and extensive, rapid recycling of ring material in which moons are continually shattered into ring particles, which can then reform into new moons.