Planet Mercury, 2nd flyby of Mercury by NASA Messe - The NASA spacecraft Messenger has made its second flyby of the smallest planet in the Solar System and the one closest to the Sun, Mercury. Passing very close to the surface of planet. The bright crater Kuiper is near the center and slightly below. This was identified in the 1970's by the Mariner 10 spacecraft. Read more and see more images at the Messenger website. http://messenger.jhuapl.edu/gallery/sciencePhotos/view.php?gallery_id=2