Why is the starry sky the Sky Zoo?

In order to study the starry sky systematically and scientifically and conduct academic exchanges, the International Astronomical Union made a unified regulation in 1928: according to the "longitude" and "latitude" in the sky (called right ascension and declination), the whole day was divided into 88 constellations of different sizes, and their names were kept to take care of historical habits. Therefore, except for those constellations located in the south, which have been studied until modern times and have the names of modern instruments such as "microscope", "clock" and "green tube", most of them are animals or mythical figures.

Coincidentally, among the 88 constellations, 44 are animals, accounting for exactly 50%. If Mu Fu, Orion and Snake Man are added, the proportion will be as high as 2/3. It can be seen that there are not only big bears and little bears in the sky, but also phoenixes and unicorns that are not found on the earth. It is really a large-scale "zoo". In this zoo, there are 20 kinds of mammals (hounds, dolphins, etc.). ), 8 species of birds (peacocks, pigeons, etc. ), 5 kinds of reptiles (giant snake, long snake, etc. ), 4 kinds of fish (flying fish, swordfish, etc. ), 2 kinds of insects (flies, etc.). ), and five mythical animals (dragon, horse, phoenix, etc. ).