Sounds of the Vacuum
In a vacuum there are no sounds, it is said, because sound is a carrier substance,
like gas or liquid needed to spread.
But our universe is not still, on the contrary - the cosmos is full of rotating stars (pulsars),
Plasma storms, changes in magnetic fields, eruptions and stellar thunderstorms - only human ears can
do not perceive / hear them.
There are exceptions:
Where planets or moons have a gas atmosphere - e.g. Mars, Venus or Titan - were
individual sounds recorded with on-board seismographs.
Most of the “sounds” in the universe, however, come from the spectrum of electromagnetic waves that we cannot perceive - from radio signals to microwaves to gamma rays.
For decades, probes such as Voyager or Cassini, but also radio telescopes all over the world,
such “sounds / phenomena” with special devices - radio plasma wave instruments or magnetometers.
Space agencies such as the National Aeronautics and Space Administration (NASA),
the European Space Agency (ESA), universities and private astronomers shift the mostly low frequencies into the audible range (between 20 and 20,000 Hertz) and present them to the public.
The sounds of space seem strange and familiar at the same time.