Editing Sidereus Nuncius (section)

===Moon===
In observing the Moon, Galileo saw that the line separating lunar day from night (the [[Lunar terminator|terminator]]) was smooth where it crossed the darker regions of the Moon but quite irregular where it crossed the brighter areas. From this he deduced that the darker regions are flat, low-lying areas, and the brighter regions rough and mountainous.<ref name="larb2014"/> Basing his estimate on the distance of sunlit mountaintops from the terminator, he judged, quite accurately, that the lunar mountains were at least four miles high. Galileo's [[engraving]]s of the lunar surface provided a new form of visual representation, besides shaping the field of [[selenography]], the study of physical features on the Moon.<ref name="Raphael"/>

[[File:Pleiades Sidereus Nuncius.png|thumb|left|200px|Galileo's drawings of the Pleiades star cluster from ''Sidereus Nuncius''.]]