Understanding Earth means understanding some of its most extreme environments, including the cold, icy reaches known as the cryosphere. Beyond just the frozen polar regions, the cryosphere extends into our planet's temperate latitudes, including snow cover, glaciers and the layer of frozen soil known as permafrost. This year, we're launching two new NASA Earth satellites that will help further our knowledge of the cryosphere. The Gravity Recovery and Climate Experiment Follow-On (GRACE-FO) and t