Using real data from NASA's GRACE satellites, students will track water mass changes in the U.S., data that measures changes in ice, surface and especially groundwater. The background information includes an animated video about where water exists and how it moves around Earth, as well as short video clips to introduce the GRACE mission and explain how satellites collect data. Students will estimate water resources using heat-map data, create a line graph for a specific location, then assess trends and discuss implications.

This activity illustrates the importance of water resources and how changes in climate are closely linked to changes in water resources. The activity could fit into many parts of a science curriculum, for example a unit on water could be connected to climate change.