Refracting telescope focus, results in a non-inverted and upright image. Galileo’s best telescope magnified objects about 30 times. Because of flaws in its design, such as the shape of the lens and the narrow field of view, the images were blurry and distorted. Despite these flaws, the telescope was still good enough for Galileo to explore the sky. The Galilean telescope could view the phases of Venus, and was able to see craters on the Moon and four moons orbiting Jupiter. Parallel rays of light from a distant object (y) would be brought to a focus in the focal plane of 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"