The landing of U.S. astronauts on the surface of the moon could have been a disaster for mankind. An article on the subject was published by the British newspaper Express, whose correspondents recalled the fears that existed due to the possible contamination of the Earth with lunar microorganisms.
In the late sixties, the scientific community had serious concerns dictated by the possible contamination of Earth by alien bacteria. If microbial life existed on the moon, having visited it, American astronauts could have brought alien bacteria to Earth, and it could have caused a planetary disaster.
“Such a risk was not significant at all, but it still could not be ignored. At the time the Apollo 11 mission was prepared, no one knew for sure if there was bacterial life on the Moon. If there was, U.S. astronauts, spacecraft or probes returning from the Moon could have infected our planet with alien bacteria,” the British publication writes.
It was originally assumed that U.S. astronauts would have to live for three weeks in quarantine after returning from the moon, but then they decided to abandon these plans. NASA management decided that the astronauts would be exposed to psychological discomfort if they could not see their family and friends immediately after landing, so the quarantine was canceled. People were lucky that there were no bacteria on the moon.