“Hear” the cosmos: from dark matter to comet Churyumov – Gerasimenko

It is known that sound does not spread in airless space. But space cannot be called dumb. We tell how planets and other space objects “sound”, and where to listen to them.

^{NASA / Unsplash Photos}

Radio for Dark Matter

Dark matter – makes up a large part of the universe. Scientists know (thanks to gravitational anomalies) that dark matter exists, but it has not yet been registered. It does not emit light, as well as any other electromagnetic radiation visible to modern telescopes. A group of physicists has proposed a way to detect dark matter – to “listen” to it. They are developing a kind of "radio" based on gravitational wave detectors. They will trap axions – hypothetical neutral particles that hold protons and neutrons together – which are an essential part of cold dark matter.

This year, physicists from Stockholm University proposed an approach that will enhance the effect of "radio". They suggested that the electric field of axions can be used to create oscillations in the plasma, which will make the signal more pronounced.

Note that in 2017, a similar project began to be developed at Stanford University. The basis of their "radio" for dark matter was the concept of wave-particle duality. It assumes that material microscopic objects exhibit the properties of waves under certain conditions, and, under others, the properties of particles. And these waves can be detected with antennas and resonators. You just need to tune in to the frequency of dark matter. The signal is likely to be very weak, so engineers are additionally developing highly sensitive magnetometers. They can sense fields with induction of less than one femtogauss. While scientists are trying to "hear" dark matter, some sounds of space can be heard now.

Black hole and the "voice" of Jupiter

So that we can hear how the planets and other celestial bodies “sound”, physicists transform electromagnetic waves into sound waves. This is a creative process that is similar to making music. Cosmic radiation was first converted to sound in 1996. Then the Galileo probe recorded Jupiter's electromagnetic waves. True, later it turned out that these were charged particles from the planet’s satellite – Ganymede.