Stellar Cartographies

Happy New Year fellow astronavigators!

First blog of the decade and let me start with wishing you all a happy new year! The coming decade promises a lot of advancements in astronomy and spaceflight, but will equally challenge us with social media issues and climate change.

The return of the seasons and of sunlight is being celebrated. Exactly after one revolution around the Sun, a year after just the same happened. Astronomy is used as the basis of our calendar. Let's take a look at the star map. How do we map out the celestial mechanics to understand seasonal climates, and later even to navigate the world with the stars?

As you all have noticed, our game makes use of such a classic star map, based on equatorial coordinates. This way of mapping the stars dates back to Hipparchus of Nicaea's astrometric measurements in the 2nd century BC. He was probably the inventor of the astrolabe and armillary sphere while he was making his famous star catalogue. The relation to the Earth axis rotation is key in under standing the 24h Right Ascension. Hipparchus is particularly famous for his accidental discovery of the precession of the equinoxes.

In this blog I want to discuss different ways of looking at a star map and different coordinate systems linked to it. In th