Lunar craters Lunar craters Lunar craters are impact craters on Earth's Moon. The Moon's surface has many craters, almost all of which were formed by impacts. The word "crater" was adopted from the Greek word for vessel - (Κρατήρ a Greek vessel used to mix wine and water). Galileo built his first telescope in late 1609, and turned it to the Moon for the first time on November 30, 1609. He discovered that, contrary to general opinion at that time, the Moon was not a perfect sphere, but had both mountains and cup-like depressions. These were named craters by Schroeter (1791), extending
History of the telescope the Galilean telescope for these early forms of telescope that employed a negative lens. Johannes Kepler first explained the theory and some of the practical advantages of a telescope constructed of two convex lenses in his "Catoptrics" (1611). The first person who actually constructed a telescope of this form was the Jesuit Christoph Scheiner who gives a description of it in his "Rosa Ursina" (1630). William Gascoigne was the first who commanded a chief advantage of the form of telescope suggested by Kepler: that a small material object could be placed at the common focal plane of the objective and