Part 16 of a series reassessing the documentary record behind the 1933 Magenta narrative. TL;DR Historical Palomar plates contain unexplained, star-like marks. Some have been recovered by a separate detection pipeline; that establishes reproducible marks in the scans, while their physical origin remains disputed. The Earth-shadow claim has several reported significances under different comparisons. The original paper’s coverage-adjusted result is 7.6σ, rather than its idealized 22σ headline....