~30,000 BC: First notations of the number of days in a lunar month - marks on animal bones (Marshack).
~2000 BC: Stonehenge - the first lunar observatory? Long sides of “station rectangle” point to extreme north position of the Moon. (Journal for the History of Astronomy 5, 71-90; 1974).
460-370 BC: Democritus: Speculated that markings on Moon were mountains.
408-347 BC: Eudoxus: Explained (adequately but incorrectly) daily, monthly and 18.6 yr (eclipse or saros) motions of the Moon by the invention of concentric spheres (epicycles)
~260 BC: Aristarchus: Devised geometric methods to estimate distance and size of Moon.
~150 BC: Hipparchus: First accurate measurements of distance and size of the Moon.
46-120+AD: Plutarch: Concerning the Face Which Appears in the Orb of the Moon - Speculated that light and dark markings were reflections of land and seas on Earth. More of Plutarch’s Moon writings are in his book, Concerning Nature in chapter 25-31 - Concerning the Moon
~500 AD: Aryabhata I: Determination of Moon’s size and distance (following Hipparchus) by Hindu astronomer.