Critical Evaluation of Studies Alleging Evidence for Technosignatures in the POSS1-E Photographic Plates

Recent studies by B. Villarroel and colleagues have assembled and analyzed datasets of unidentified features measured from digital scans of photographic plates captured by the first-epoch Palomar Observatory Sky Survey (POSS1) in the pre-Sputnik era. These studies have called attention to (i) a purported deficit of features within Earth's shadow; (ii) the sporadic presence of linear clusters; and