Debris was found in Roswell, New Mexico, in 1947. The US military initially described it in a press release as a 'flying disc,' but later stated it was a weather balloon. The Air Force retroactively linked the debris to Project Mogul, a high-altitude balloon program designed to collect intelligence [1].
The discrepancy between the initial announcement and the later explanations, along with subsequent stories and testimonies about alien beings and a cover-up, made the incident famous and controversial [1]. There is also a story about alien bodies being recovered, but it is based on an unnamed source, and no verified evidence of aliens or an extraterrestrial craft has been presented [2][3].