We know that there is sound on planets and moons in the solar system – places where there's a medium through which sound waves can be transmitted, such as an atmosphere or an ocean. You may have been told definitively that space is silent, maybe by your teacher or through the marketing of the movie Alien – 'In space no one can hear you scream'. The common explanation for this is that space is a vacuum and so there's no medium for sound to travel through. Space is never completely empty – there are a few particles and sound waves floating around.Charged particles in space can generate and be affected by electric and magnetic fields, which gives rise to the plasma-equivalent of sound waves: magnetosonic waves A researcher from Queen Mary University of London explains that space is never completely empty - there are a few particles and sound waves floating around. Sound waves around Earth are vital to our continued technological existence.