In 1989, Bob Lazar went public claiming he worked at a facility called S-4 near Area 51, where he was tasked with reverse-engineering one of nine extraterrestrial spacecraft. He described the craft's propulsion system as using Element 115 (moscovium), which was not synthesized by scientists until 2003. While Lazar's education and employment records cannot be verified (he claims they were erased), his knowledge of Area 51's layout and operations was confirmed by investigative journalists. Skeptics note that heavy elements beyond uranium were predicted by nuclear physics, and synthesized moscovium is highly unstable — unlike the stable isotope Lazar described.