Astrogeology maintains the highest quality data on the brightness of the Moon via the Lunar Calibration Program. These data are used to calibrate many spaceborne Earth observing instruments, including the Moderate Resolution Imaging Spectroradiometer (MODIS). Lunar calibration is planned by virtually all future operational satellite missions including National Oceanic and Atmospheric Administration (NOAA) (GOES-R ABI), USGS (Landsat 8 OLI), NASA (NPP-VIIRS and JPSS), European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) (MTG FCI and EPS), and Japanese, Chinese, and Indian meteorological agencies. Calibration is essential in order to compare data collected by different instruments over the decades, thus allowing climate and land use changes to be accurately assessed.