According to American astronauts Buzz Aldrin and Michael Collins, the Apollo 11 mission could have brought lunar germs back to Earth. Some errors in the decontamination procedure during the landing were the source of this risk.
On July 20, 1969, the American astronaut Neil Armstrong set foot on the Moon, a great first for humanity. The spacecraft carrying the crew of the Apollo 11 mission had been launched from the Kennedy Space Center four days earlier by the giant rocket Saturn V. For the 50th anniversary of this event, it will be possible to relive the mission in augmented reality on the initiative of the John F. Kennedy Presidential Library.
Upon their return to Earth, the astronauts had landed in the Pacific Ocean. According to an article in Space on July 6, 2019, errors in the contamination procedure could have allowed lunar germs to contaminate the Earth. According to Michael Collins and Buzz Aldrin—the other members of the mission—NASA, however, showed the will to take all precautions to avoid a health scandal.
For example, the three astronauts wore special clothing to prevent lunar germs from attaching on them. They even spent several days in quarantine to avoid any contamination.
Buzz Aldrin stated that the post-landing cleaning was done with a specific cloth. On the other hand, beyond the fact that this kind of cleaning in itself seems quite surreal, it turns out that the cloth was subsequently thrown into the water! The astronaut estimated that in case of actual contamination, the lunar germs would have been driven to the bottom of the water.
He, however, wondered whether it was possible for these microbes to survive. Before that, a first mistake was made: the hatch of the module had been opened without any precaution.
The Moon was declared sterile only after the Apollo 14 mission (1971). Before that, NASA thought there might be microbes on it, but did not really believe it. This may explain the laxity in the decontamination procedure.