Astronauts rarely allow themselves to make statements about extraterrestrial civilizations and evidence that we are not alone in the Universe. However, such statements do happen. Some American astronauts said that UFOs were during the landing of people on the moon.
In addition, the Russian cosmonauts also talked about their belief in the existence of extraterrestrial civilizations and could even see various flying vehicles during space flights. Such statements are not always taken seriously, even given the seriousness of their profession.
So can their words be real evidence of the existence of aliens, or are they fairy tales that have nothing to do with reality? Yang Liwei is the first astronaut from China, and he said that during his first flight in 2003, a mysterious incident occurred. He allegedly heard something or someone knocking on the spaceship.
Such words sound rather strange, because could not a rational being knock on the door and ask permission to enter? The Chinese astronaut added that he even looked out the windows to find the source of the knocker. When Liwei returned to Earth, he asked the specialists to recreate a similar sound, but nothing came of it.
In NASA, commenting on Ian's story, they said that nothing like this had happened before, but this does not mean that the source of the sound was aliens. Maybe some space object hit the ship and the whole reason lies in the suspiciousness of the astronaut from China?
But how to explain other statements of people who have been in space and are sure that alien civilizations exist?