Exploration of the Moon invention of the telescope, an increasing number of people began to recognise the Moon 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. Later in the 17th century, Giovanni Battista Riccioli and Francesco Maria Grimaldi drew a map of the Moon and gave many craters the names they still have today. On maps, the dark parts of the Moon's surface were called "maria" (singular "mare") or seas, and the
City on the Moon City on the Moon City on the Moon is a science fiction novel by Murray Leinster. It was released in 1958 by Ace Books under authority from Thomas Bouregy & Co using their Ace Double imprint reference number D-277. The novel details the events that unfold subsequent to an apparent sabotage attempt made against a lunar jeep on its return journey to the multinational civilian lunar city. This story was first published by Avalon Books in 1957. "City on the Moon" forms part of the To the Stars series by the same author, with two preceding books being "Space Platform"