What happened
Aldrin saw a light out the window that seemed to move alongside the spacecraft. Through the monocular, with the focus sharpened, he described it as sort of L-shaped; other retellings call it a cylinder. The crew asked Houston where their S-IVB booster was and, Aldrin later said, were told it was far away. The crew discussed the sighting in the Technical Crew Debriefing of July 31, 1969. In the 2005 documentary First on the Moon, his remarks aired but his explanation was cut. He told NASA's David Morrison he believed it was one of the four panels that enclosed the lunar module, and he wrote in 2015 that it was not an alien. A 2018 tabloid story that a "voice analysis" showed he had seen aliens was not an interview with Aldrin.