There isn't a specific asterism that is universally considered significant by almost every ancient culture on Earth. However, certain star patterns have held cultural and mythological significance in various civilizations throughout history. Here are a few examples:
Orion: The constellation of Orion, with its distinctive belt of three stars, has been recognized and mythologized by several ancient cultures, including the Egyptians, Greeks, and Native Americans. It often symbolized a hunter or warrior and was associated with myths and legends in different societies.
Ursa Major and Ursa Minor: The constellations Ursa Major (the Great Bear) and Ursa Minor (the Little Bear) have been recognized by many cultures and have served as navigational aids for centuries. Ursa Minor contains the North Star (Polaris), which has been important for celestial navigation.
Pleiades: The Pleiades, a cluster of stars in the constellation Taurus, have held significance in various cultures. They feature prominently in Greek mythology and were associated with agriculture, seasonal changes, and navigation in different societies worldwide.
Southern Cross: The Southern Cross, a constellation visible in the Southern Hemisphere, has been important for navigation and has cultural significance for indigenous peoples in Australia, New Zealand, and other southern regions.
It's important to note that while these star patterns have held significance for many ancient cultures, the interpretations and specific myths associated with them can vary among different societies. Additionally, the notion of a universally significant asterism across all ancient cultures is not supported by historical evidence.