Archaeologists on the island of Nuku Hiva have discovered several Manganese-Inscribed obsidian mirrors within a high-status ceremonial plaza. The back of each mirror is etched with symbols using a dark manganese-based pigment, depicting the rising of the Pleiades and other key navigational constellations. These mirrors were likely the focal point of the Star-Reflection festival, where priests would capture the reflection of specific stars in pools of water or on the mirrors' polished surfaces to predict the success of upcoming voyages.
The discovery is significant as it provides the first physical evidence of a formal astronomical festival in the Marquesas that used specialized optical tools. The chemical fingerprint of the obsidian confirms it was brought from a distant volcanic source, indicating that the festival was an event of regional importance that drew participants from across the archipelago. This research highlights the sophisticated intersection of religion, astronomy, and navigation in ancient Polynesia.