Creepy Knocking Sound Presumed to Be Aliens Heard By China's First Astronaut

China has just proven that they are ready to take the international stage when it comes to space exploration. But China's first astronaut, Yang Liwei, revealed that while on space, he has heard a mysterious knocking sound.

Yang Liwei is the very first Chinese astonaut. He is the one who piloted the first manned spacecraft of China, which they call as Shenzhou-V. While inside the spacecraft, the astronaut heard an eerie knocking sound. Although the incident occurred in 2003, he is still enthusiastic in telling details about that mysterious experience. He said that the sound felt more like "someone knocking the body of the spaceship just as knocking an iron bucket with a wooden hammer," He added further "It neither came from outside nor inside the spaceship."

The astronaut admits that the knocking sound made him felt uneasy that he even have to look outside the porthole to find the cause, but can't find anything. Even sound experts failed in trying to determine what it was.

Until now, the issue of hearing a knocking sound in space remains to be a mystery. What could have caused the incident is still unknown despite the many trials that experts did to unveil the possible reason. It should be noted that no sound can travel space because of the lack of medium. Professor Goh Cher Hiang of the National University of Singapore said "The traveling of sound requires a medium - be it air particles or water molecules or metal, solid atoms," and he added. "If it is knocking, there could be something physical hitting the spacecraft carrying the astronaut".

On the other hand, Hiang's colleague named Wee-Seng Soh had another guess, he said that the sound could be "a result of expansion or contraction of the spaceship, especially since the temperature of the spaceship's exterior could change considerably within the orbit."