Snow and ice cover has a profound impact on the overall health of the planet. This frozen part of the world is called the cryosphere and the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument on board the Suomi National Polar-orbiting Partnership (Suomi NPP) satellite -- and the forthcoming satellites of NOAA's JPSS constellation -- helps experts determine how the cryospehere is changing and to what effect.