In 2014, Jacob & Co perfect shocked the watch industry with the launch of the astronomical gravity three-axis tourbillon watch. This year, the brand has extended Astronomia’s innovation even further with the launch of Astronomia Sky, adding an unprecedented complication: a three-dimensional star display combined with an elliptical sky indicator and a 24-hour day and night display. To understand the complexity of this feat, we’ll examine each innovation individually.

The celestial dial covers the inner surface of the planetarium case and completes one full revolution in a sidereal year – the actual time it takes Earth to make one full revolution around the sun relative to a fixed star. The blue grade 5 titanium dial features 18K gold stars and hand-set and hand-engraved zodiac signs.

Above the celestial dial is the oval sky indicator, which shows the portion of the star visible from the northern hemisphere. The indicator makes one full rotation in a sidereal day. A sidereal day is the time it takes for the Earth to rotate once around its axis: 23.5640916 hours.perfect watch

At the center of the satellite axis, a painted, hand-engraved titanium sphere spins within a tinted half-dome sapphire, symbolizing night and day.

Four satellite arms rotate around the dial every 20 minutes. As a result, when one looks at a watch, it will never be exactly the same. On the first satellite is the amazing three-axis gravitational tourbillon, which rotates around one axis in 60 seconds, the second axis every 5 minutes, and the dial every 20 minutes. On the second satellite is the time (hours and minutes) subdial. Thanks to a clever differential gear system, the time display is always in the correct position as it rotates around the dial. The “12” mark always faces up. On the third satellite is the orbital seconds hand, a skeletonized titanium wheel with a seconds hand that rotates around the dial every 60 seconds and every 20 minutes. On the fourth and final satellite is the patented “Jacob Cut” red moon, a spherical orange sapphire with 288 facets.

Jacob & Co. created a simple and ingenious solution for the time setting of this complication watch. The Astronomia Sky has two bows and two wheels on the back, allowing users to easily set the time. One bow is used to set the time and day/night indicator (both based on 24-hour solar time), while the other bow is used to wind the mechanical movement. While one wheel sets the stars, the other wheel sets the elliptical sky indicator. Known for its unique and captivating complications, Jacob & Co. has made history again with the Astronomia Sky.