Moon the correct values of about 60 and 0.273 respectively. Archimedes (287–212 BC) designed a planetarium that could calculate the motions of the Moon and other objects in the Solar System. During the Middle Ages, before the invention of the telescope, the Moon was increasingly recognised as a sphere, though many believed that it was "perfectly smooth". In 1609, Galileo Galilei drew one of the first telescopic drawings of the Moon in his book and noted that it was not smooth but had mountains and craters. Telescopic mapping of the Moon followed: later in the 17th century, the efforts of Giovanni
Ghost craters on Mercury interpreted to have formed after the wrinkle ridges. If a graben cuts across a ridge and appears to be modified, then it is interpreted to be older, and to have formed before the ridges. The presence of both graben and wrinkle ridges within ghost craters is a feature unique to Mercury. This combination is because of the tectonic processes that formed the graben and wrinkle ridges. The graben and wrinkle ridges came from rapidly accumulating lava flows that cooled within impact craters while the planet was experiencing global contraction from interior cooling. Other planetary bodies such as the Moon and