Overview
- The full phase occurs at 00:14 on Dec. 5 in peninsular Spain, with prime viewing the night of Dec. 4 across the Americas if skies are clear.
- NASA notes a supermoon can appear up to about 14% larger and 30% brighter than a full Moon at apogee, though the difference is subtle to the eye.
- Astronomy services characterize this setup as unusually extreme near the winter solstice, with a similar configuration not forecast again until 2042.
- This is the third and final supermoon of 2025, traditionally known as the Cold Moon or Long Night Moon.
- December also features the Geminids meteor shower active Dec. 4–17 with a Dec. 14 peak near 120 meteors per hour, plus a Dec. 3 Moon–Pleiades close pass.