Astronomical clocks have been around for centuries and people have been studying the stars and the planets for way longer than that.
So it isn't a surprise to see astronomical devices that, apart from telling time, gather information like the position of the Sun and Moon relative to the Earth at a certain point of the year. The Prague Astronomical Clock is one of the oldest functional ones to date. Here are some information behind how it was built and how it works.
(Image credit: Wikimedia Commons)
