The cold shimmer of a starry night. The diaphanous presence of a large mother-of-pearl moon. The pale gleam of platinum. Perpetual Moon 41.5 Platinum “celestial blue” is expanding the collection’s different variations on the largest astronomical moon. Every part of this piece evokes the radiance of the night, from the dial stamped with the House’s “Stellar Rays” decor to the moon disc in a grained sky and the navy-blue alligator-leather strap.