1. Astronauts were placed in quarantine after returning from the moon.
    "There is a famous image of President Nixon talking to the Apollo 11 crew consisting of Michael Collins, Neil Armstrong and Buzz Aldrin. This continued until after the Apollo 14 crew returned safely. After this it was decided that the Moon did not contain any deadly diseases. The Apollo 13 crew, who had a malfunction and had to return to Earth, did not have to be quarantined after their re-entry as they didn’t actually walk on the moon." http://www.armaghplanet.com
  2. Space is silent
    There is no atmosphere in space. No atmosphere = nothing for sound waves to travel though = silence
  3. Neutron stars can spin at a rate of 600 rotations per second.
    "Neutron stars are one of the possible evolutionary end-points of high mass stars. They're born in a core-collapse supernova star explosion and subsequently rotate extremely rapidly as a consequence of their physics. Neutron stars can rotate up to 60 times per second after born. Under special circumstances, this rate can increase to more than 600 times per second." https://astronomy.swin.edu.au/cosmos/N/Neutron+Star
  4. The Apollo astronauts' footprints on the moon will probably stay there for at least 100 million years.
    There is no wind on the moon since there is no atmosphere, so there is nothing to remove the footprints!