NASA Measures ‘Moonlight’ to Improve Earth Observations

In March 2025, NASA pilots took the agency’s ER-2 science aircraft on a series of night flights over NASA’s Armstrong Flight Research Center in Edwards, California, as the Moon increased in visible size. The Airborne Lunar Spectral Irradiance, or air-LUSI, mission observed the Moon at different phases and measured the sunlight reflected by the lunar surface. Specifically, the instrument tracked the amount of light reflected at different wavelengths. This information enables scientists to use the Moon as a calibration tool for Earth-observing sensors. The air-LUSI project is a collaboration between scientists and engineers from NASA, the National Institute of Standards and Technology, the U.S. Geological Survey, the University of Maryland Baltimore County, and McMaster University in Ontario.