Introduction

Well, I will use the first entries to explain a little what this is. The idea is to upload regularly interesting little things related to astronomy, particularly what is called the visible sky, so the one can be directly observed by human eyes without any additional element. This is, therefore, the sky Greeks, Egyptians, Babylonians and Aztecs were watching at and the only one that they knew. The knowledge acquired and transmitted by various civilizations is what led us to set the map of 88 constellations that define the night sky.

The constellations, as many of you already know, are nothing more than arbitrary groupings of stars that, from the point of view of the earth's surface, appear to be spatially close to each other but, in fact, may be extremely remote. Today, despite being very well demonstrated the falsity of the geocentric model, to locate stars in the sky is still considering it as a sphere surrounding the Earth and its surface is painted with the stars. Between this surface and the earth the planets (Greek name came to mean "moving stars") are moving. This planets originally included the Sun, Moon, Mars, Mercury, Jupiter, Venus and Saturn, the only planets known by the ancient Greeks.

Grouping these stars in constellations come to separate the night sky in different regions to help astronomers locate stars in the sky. The result can be seen in the picture below which shows that any point in the sky belongs to a constellation even though at this point there is no star.

Step by step, we will analyze the different constellations and regions of the sky. I hope you'll enjoy with me during this journey.