Yes, outer space is completely silent because sound needs a medium, like air, water, or a solid surface, to travel. Sound waves are vibrations that move through particles, but in the vacuum Space roar: The mystery of the loudest sound in the universe Space Space Comm Expo Europe Vibration Testing Data Physics ESA Flexible satellite completes vibration tests The Sounds of Spacetime American Scientist Cosmic Sound Comparison What Would Space Sound Like?! Space is silent to human ears but the universe still creates powerful vibrations and signals. The Sun giant