Every Full Moon, This Satellite Stops Watching Earth and Turns to Face the Moon Instead

Once a month during a full Moon, Landsat 9 turns away from Earth to image the lunar surface, using the Moon's stable and predictable reflectivity to detect and correct any drift in its sensors. This calibration process helps ensure that Landsat's Earth observations remain accurate and consistent across its decades-long data record. Along with lunar scans, engineers also cross-check data against uniform ground sites and on-the-ground measurements to maintain the reliability of Landsat imagery.