With its sweeping 2,330-km-wide viewing swath, MODIS sees every point on our world every 1-2 days in 36 discrete spectral bands. MODIS maps the areal extent of snow and ice brought by winter storms and frigid temperatures. The daily and 8-day composite snow-cover products (at 500-m resolution) are consistently generated from automated snow-mapping algorithms. Long term availability of MODIS-type snow-cover data is a key to study the connection between snow-cover change and global climate change.