Autumn Equinox 2026
the one morning the whole sky agrees — sunrise due east, everywhere
drag to rotate · tap a gold pin to read its alignment
How this is computed
The sun's position uses the NOAA Solar Calculator (Spencer 1971 truncated series) — declination accurate to about 0.05°, the equation of time to about half a minute. The moon and the deep-time scrubber use Meeus, Astronomical Algorithms (2nd ed.). Ancient solar and lunar alignments are pinned from archaeological literature (Ruggles, Astronomy in Prehistoric Britain and Ireland), not derived from the model. Good for contemplation, not for navigation.