Determine the origin of pre-Sputnik transient events in photographic plates
Determine the physical origin of the transients detected in digitized pre-Sputnik astronomical photographic plates, including multi-transient alignments and the 19 July 1952 triple transient, specifically whether they are solar reflections from artificial objects in geosynchronous orbit or atmospheric/exoatmospheric phenomena involving multiple stationary light sources.
References
Although a few preliminary candidates have been identified \citep{Villarroel2022c}, the origin of these transients remains unknown.
— A Cost-Effective Search for Extraterrestrial Probes in the Solar System
(2510.17907 - Villarroel et al., 19 Oct 2025) in Section 2.1 (Going back in time: using pre-Sputnik images)