(IDEX Online) - One of Patek Philippe's rarest watches has broken the record for the highest price paid in an online auction.The Sky Moon Tourbillon, with a blue handmade enamel dial and white gold hand-carved case, sold for $5.8m at Christie's Hong Kong.It is one of the most sophisticated timepieces ever created, with functions that include a cathedral minute repeating, tourbillon, perpetual calendar, retrograde date, moon phases, leap year indication, sidereal time, sky chart, phases and orbit of the moon.The watch takes the record for the highest price at an online auction, as distinct from an online bid at a physical auction. That record's held by a a Philippe Dufour Grand Sonnerie, which sold for $7.63m in 2021. Pic courtesy Christie's