Agriculture and the Landsat program have a long history together. The satellite Earth observations that began in 1972 provided a vital ability to monitor how crops were growing around the world—and whether shortages might be looming that would affect the food supply. When later Landsat satellites carried thermal instruments to measure land surface temperatures, scientists gained an important tool for estimating how much water was being consumed by crops because evaporation and transpiration (plant “sweat”), collectively known as evapotranspiration (ET), cool down an area. Today, U.S. farmers and water managers rely on past and current Landsat data as the backbone of models that help them determine how much water the crops are using.