What are constellations?
The entire sky (half of which is above the horizon at any moment) is divided into 88 constellations. The constellations and their borders have nothing to do with science. The stars in a particular constellation are not necessarily related to one another, nor are they even near each other in space. The constellations recognized by astronomers in the northern sky come from ancient Greek and Roman mythological star-pictures. The southern constellations were named by the first Western mariners to explore southern waters. Other cultures have their own constellation patterns, which do not necessarily match “classical” ones. Constellations cover much too broad an area of space to be imaged by the Hubble Space Telescope (HST), and there really is no reason for HST to photograph constellation patterns even if it could be done.
There is a word for a pattern of stars in the sky which appears to be so distinctive that it is easily identifiable and remembered. That word is “asterism”. In ancient times, people saw asterisms and made up all kinds of stories about mythological creatures and characters which they associated with the star patterns. As astronomers subsequently began to make maps of the stars, the named asterisms were included in the maps and called constellations. As time passed, the sky became filled with constellations, many of which included the same stars. The International Astronomical Union stepped in to gain control and make sense of things in 1925. They adopted 88 official constellations and assigned areas of the sky to specific constellation names. It should be noted, however, that they made no requirement that the constellation be easily seen nor that the legends associated with the constellation make any sense. In fact, most constellations don’t really resemble the creatures or characters t
