English: During its mission, the Galileo spacecraft returned a number of images of Earth's only natural satellite. Galileo surveyed the moon on its way to explore the Jupiter system. This colour mosaic was assembled from 18 images taken by Galileo's imaging system through a green filter. On the upper-left is the dark, lava-filled Mare Imbrium, Mare Serenitatis (middle left), Mare Tranquillitatis (lower left), and Mare Crisium, the dark circular feature toward the bottom of the mosaic. Also visible in this view are the dark lava plains of the Marginis and Smythii Basins at the lower right. The Humboldtianum Basin, a 400-mile impact structure partly filled with dark volcanic deposits, is seen at the centre of the image.