Gustavo Rivas — Avellaneda, Province of Buenos Aires

Official source account — 2020 annual report, printed page 145: Gustavo Rivas saw and photographed a shaped object until it passed behind a sign. CIAE found a form consistent with a commercially sold decorative balloon, a steady wind-driven course and a hanging vertical string revealed by IPACO. Those features supported a helium balloon that had escaped or been released. The agency classified the conventional identification Type A. The summaries distinguish reported observations from the agency’s proposed explanations. Source Type A/B ratings describe explanatory confidence and are not encounter classes. The map uses an approximate GeoNames locality centroid, not the observation point.