Every one of the 216 declassified PURSUE documents carries three facts that can be cross-cut: the form that was reported, the place it was reported, and the year it happened. Lay them against each other and the reported shape stops looking random. It moves.
The headline the matrix shows: the dominant reported form changes by era. Discs and saucers own the 1940s and 50s. Cylinders and Tic-Tacs cluster through the modern pre-2020 record. Orbs and spheres take over the 2020s. Whether that is the phenomenon changing, the sensors changing, or the culture of description changing is the open question, but the drift itself is in the government's own files. The same drift is traced shape by shape on Morphology.
A second pattern Tranche 4 sharpens: the nuclear-site column is no longer a single 1940s cluster. Toggle “nuclear-proximity only” and the same geography now runs across eras, from the green fireballs over the New Mexico complex in 1949 to a diamond-shaped object over the Pantex weapons plant in 2015. The reported shape drifts, but the address holds. Follow it end to end on Nuclear Sentinels.