Constellations and asterisms are related to the grouping of stars in the night sky, but they have distinct differences.
Constellations: Constellations are specific areas of the celestial sphere that are recognized and defined by astronomers. They are formalized patterns or configurations of stars that form a shape or figure, often representing mythological characters, animals, or objects. Constellations help astronomers navigate and map the night sky, making it easier to locate specific celestial objects. There are 88 officially recognized constellations, covering the entire sky.
Asterisms: Asterisms, on the other hand, are informal star patterns or groups that are not officially recognized or defined by astronomers. They are smaller and more recognizable patterns within constellations or across multiple constellations. For example, the Big Dipper (part of the Ursa Major constellation) and the Summer Triangle (formed by stars from the constellations Cygnus, Aquila, and Lyra) are popular asterisms.
As for popularity, it can vary depending on cultural, historical, and regional factors. Constellations, with their formal recognition and long-standing traditions, tend to be more widely known and referenced. They are commonly used for navigation, storytelling, and cultural identification. Many ancient civilizations and cultures developed their own constellations based on their myths and beliefs.
Asterisms, while not officially recognized, often gain popularity due to their distinctive shapes or visibility. Some asterisms are widely recognized and used by stargazers and amateur astronomers to locate other celestial objects or as reference points. Their popularity can also be influenced by cultural significance or being featured in popular literature, art, or folklore.
Overall, constellations have a broader and more universal recognition due to their formal status and historical significance, while asterisms can be popular among enthusiasts and casual observers for their distinctiveness and usefulness in identifying stars and other objects in the night sky.