Ultra hires moon terrain model busted with ZBrush tools. [from wiki:] Petavius is a large lunar impact crater located to the southeast of the Mare Fecunditatis, near the southeastern lunar limb. The outer wall of Petavius is unusually wide in proportion to the diameter, and displays a double rim along the south and west sides. Rev. T. W. Webb described Petavius as: "one of the finest spots in the Moon: its grand double rampart, on east side nearly 11,000 ft (3,400 m). High, its terraces, and convex interior with central hill and cleft, compose a magnificent landscape in the lunar morning or evening, entirely vanishing beneath a Sun risen but halfway to the meridian." The most favorable time for viewing this feature through a telescope is when the Moon is only three days old. By the fourth day the crater is nearly devoid of shadow.