Lunar cartography became one of Cassini’s major works: the refractors of that time were poor, and using them one could only see parts of the Moon, which then had to be joined together, while the observational conditions were, to say the least, acrobatic. Cassini did these observations himself, helped by a draftsman who made the sketches, and subsequently produced the magnificent maps that are all conserved at the Observatory. The project culminated in 1679 with the presentation at the Academy of a superb engraving with a diameter of 53 cm, which remained unrivaled until the invention of photography. Cassini adds a heart, and also a small portrait of his wife, Genevieve de Laistre (1643-1708), on a rocky promontory.

caption : Map of the Moon - copyright : Observatoire de Paris