Calculating the ebb and flow of the tide, harboring ambitions for Peter's moon trip, counteracting the restlessness of a sleepless night in good time or simply being interested in celestial processes: And looking at the sky does not always provide clarity. In order to be able to read the exact phase of the moon's change from new moon to full moon to half moon to new moon even in cloudy times, technical inventions such as the moon clock are helpful.

Assembling the AstroMedia moon clock is quite simple and, according to the manufacturer, can be completed within four to five hours. Following the example of the large medieval astronomical clocks, such as those that can still be seen in Strasbourg Cathedral and the Amalien Wing of the Vienna Hofburg, this moon clock uses a sphere to display the phase of the moon. In contrast to the two-dimensional representation of a wristwatch or wall clock, the black and white sphere, when viewed vis-à-vis, shows the shadow-light boundary of the crescent moon not as an arc, but as a straight line, as it actually appears on the celestial moon.

You can immediately see which phase the moon has just reached during its orbit around the earth: Driven by a special clockwork mechanism, the sphere rotates at the same speed as Luna and precisely depicts the current light shape of the moon, from new moon and the crescent phases of the waxing moon to half moon, full moon and the waning moon again until the following new moon. The respective age of the moon can also be read on the base, i.e. how many days the moon has been in the current cycle. A moon phase cycle lasts 29 days, 12 hours and 44 minutes from new moon to new moon - although this is an average value. This is because the speed of the earth and moon on their orbital ellipse around the sun is not constant due to the solar gravitational force - so the lunation is also subject to fluctuations. The back of the moon clock therefore shows the full moon dates calculated by astronomers up to 2035 so that you can regularly readjust the moon clock.