In an unusual perspective for an Earth-observing satellite, the Copernicus Sentinel-2 mission captured this image of the moon, Earth's only natural satellite. The Sentinel-2 mission acquired this lunar image by rolling one of its satellites sideways to view the moon instead of Earth. This is part of a regular calibration process, whereby the stable intensity of the moon's light makes it possible to detect and correct even the smallest changes in the performance of Sentinel-2's instrument. This ensures data accuracy throughout the mission, which is critical for its applications.