Telescope earliest existing record of a telescope was a 1608 patent submitted to the government in the Netherlands by Middelburg spectacle maker Hans Lippershey for a refracting telescope. The actual inventor is unknown but word of it spread through Europe. [[Galileo Galilei|Galileo]] heard about it and, in 1609, built his own version, and made his telescopic observations of celestial objects. The idea that the [[Objective (optics)|objective]], or light-gathering element, could be a mirror instead of a lens was being investigated soon after the invention of the refracting telescope. The potential advantages of using [[parabolic reflector|parabolic mirrors]]—reduction of [[spherical aberration]] and no
Zacharias Janssen claims include that his father invented the telescope in 1590, that his father invented the telescope in 1604, that he and his father invented the telescope in 1618, and that Jacob Metius and Cornelis Drebbel bought a telescope from him and his father in 1620 and copied it. Johannes also seems to have lied about his own date of birth, maybe so he could stake his own claim as inventor of the telescope along with his father. The 1655 investigation by William Boreel (who may have been a childhood friend of Zacharias Zachariassen) added to the confusion over invention. The