Is there sound in space?

The answer

Space is mostly a vacuum with too few particles to transmit sound waves as we know them. However, in dense regions like galaxy clusters, thin hot gas can carry extremely low-frequency pressure waves. In 2003, the Chandra X-ray Observatory detected sound waves emanating from the supermassive black hole in the Perseus cluster - the deepest note ever detected, about 57 octaves below middle C, with a period of 10 million years. NASA later sonified this data by raising the frequency 57–58 octaves into human hearing range, producing an eerie cosmic drone.