Claims

Nine star-like point sources are present at the reported positions on surviving glass copy material of the POSS-I red plate exposed on 12 April 1950 (field E0070), and are absent from the overlapping plate exposed six days later and from deeper modern surveys.

All nine point sources from the 12 April 1950 POSS-I red exposure (field E0070) are physically present as emulsion features on the original telescope negative itself, at their published positions — not only on downstream glass copy material.

Three point sources of roughly 16th magnitude within 10 arcseconds of each other appear on a POSS-I exposure of 19 July 1952 and are absent from the consecutive exposure taken within the hour, and from all subsequent imaging down to magnitude 25.5.

The nine April 1950 detections are systematically sharper and more concentrated than stellar images of comparable brightness on the same plate, with all nine falling on the sharp side of the plate's profile-statistic distribution.

A sub-second optical flash recorded during a long photographic exposure is expected to appear sharper and more circular than a star image, because stars accumulate seeing and guiding blur over the exposure.

The ~107,875-object VASCO working catalog shows a deficit of transient candidates inside the modeled Earth shadow at geosynchronous altitude (roughly 0.46% observed against 1.4% geometric expectation).

The Earth-shadow deficit becomes stronger at all tested altitudes after applying the quality filtering.

Transient-candidate detection rates in the ~107,875-object VASCO working catalog are elevated within one day of atmospheric nuclear weapons tests (relative risk approximately 1.45).

Transient-candidate detection rates in the VASCO working catalog decline monotonically with geomagnetic activity (Kp index), and controlling for Kp strengthens the reported nuclear-window association.

Some POSS-I multiple-transient events are reported to form linear alignments consistent with point sources along a shared sky-projected path.

When p ≥ 0.70 VASCO transients and plate-aware random controls are projected onto a shell at 35,786 km altitude and binned in 5°×5° Earth-fixed cells, 16 of the 137 cells with at least 5 expected transients show an excess over control expectation that is significant after Bonferroni correction.

Random control samples of 897 plate-aware positions, projected and clustered by the same two-step procedure, produce two or three clusters with average silhouette values of 0.50–0.60, meeting or exceeding the 0.50 threshold the authors adopt as indicating non-random clustering.

The DSS and SuperCOSMOS digitizations of POSS-I derive from separate glass copy negatives that share a common intermediate positive, so a defect introduced at the shared copy stage can appear in both modern datasets without existing on the original telescope negative.

Ordinary emulsion, copying, and scanning defects produce isolated, approximately star-like point detections on archival photographic plates at rates sufficient to contaminate single-exposure transient searches.

Independent source-extraction pipelines recover the canonical detections (eight of nine from April 1950; three of three from July 1952) and roughly two-thirds of the published 5,399-candidate catalog, without reference to the original team's software or candidate lists.

Single-exposure transient candidates analogous to the POSS-I events occur on Hamburg Observatory Schmidt plates — an independent telescope, emulsion stock, plate archive, and digitization lineage.

A subset of Hamburg transient candidates exhibits the coma aberration pattern expected for off-axis point sources imaged through the telescope optics — a signature that plate-surface artifacts should not naturally reproduce.

Artificial objects capable of producing the reported plate detections were present near Earth before the launch of Sputnik 1 in October 1957.

The reflective objects responsible for pre-Sputnik plate transients were extraterrestrial technological artifacts.

At least some of the disputed pre-Sputnik flashes were sunlight reflected from objects physically near Earth (at geosynchronous-like altitudes) rather than light from distant astronomical sources.

At least some of the disputed pre-Sputnik plate marks were produced by light entering the telescope during the original exposure, rather than being introduced afterwards in the emulsion, the copying chain, or digitization.

The near-Earth reflective population responsible for the Earth-shadow deficit in the VASCO working catalog lies at characteristic altitudes of approximately 20,000–35,000 km above Earth's surface.

The millimetre-scale particle sizes of the dusty-plasma mechanism proposed for the POSS-I transients are inconsistent with the centimetre-to-metre facet sizes inferred from transient magnitudes under the specular-reflection model, so a dusty-plasma origin is excluded unless the size inference is substantially revised.

Among the toy models considered by the VASCO group (natural reflective bodies, dusty plasma, non-human intelligence), only a non-human-intelligence scenario simultaneously accommodates all five reported features: narrower-than-stellar PSFs, groupings, the Earth-shadow deficit, the nuclear-test temporal correlation, and the geomagnetic-index anticorrelation.