The aim of this article is to discuss the speculations and conjectures involving two events that happened in Brazil in the end of the 1950's. The first one was an explosion in the skies of a city in the State of Ceará's hinterland in July of 1958. The second is the Operation Argus, conducted by the US Department of Defense, between August and September of 1958. These events were appropriated in such a way by their historical subjects that they were associated with a possible clandestine atomic test in the Northeastern part of Brazil.
Cold War; Operation "Argus"; Atomic Tests