Despite the common belief that Galileo was the originator of the telescope, it was actually first patented in 1608 by German-Dutch lensmaker Hans Lippershey, though it would not be called a "telescope" for three years, until which it was called a "Dutch Perspective Glass".  Its design involved a concave eyepiece aligned with a convex objective lens that was capable of magnifying objects by a magnitude of three.  Although Lippershey was the first to patnent his design, there is little information proving he was the origional inventor and the Instrument was greatly improved, however, a year later by Galileo, who was able to design a telescope capable of a magnification of 20 times.  This date is particularly significant since da Vinci's obvservations on the moon were made a century before the invention of the telescope.  His discoveries reguarding the moon's surface and illumination were made without any magnification or ability to see the surface with any clarity.

After making vast improvments in the telescope in 1609, Galileo was able to make detailed observations of various planets as well as the moon.  One such observation was that the moon was not the perfect spherical surface society assumed it to be, but rather was made up of various valleys, plains, and moutains much like the Earth's surface.  This gave further insight into da Vinci's observations on the various dark spots scattered throughout the moon's surface.  These discoveries were particularly radical since the moon, like the planets, were through to be perfect celestial beings and the thought of them containing imperfections would have been highly controversial.