Despite being essential to life on Earth, the magnetic field isn’t something we can actually see in itself, or ever hear. However, magnetic signals measured by ESA’s Swarm satellite mission were converted into sound – with a pretty scary result.

Thisaudio cliprepresents the magnetic field generated by Earth’s core and a solar storm.

Earth’s magnetic field is a complex and dynamic bubble that keeps us safe from cosmic radiation and charged particles carried by powerful winds flowing from the Sun. When these particles collide with atoms and molecules – mainly oxygen and nitrogen – in the upper atmosphere, some of the energy in the collisions is transformed into the green-blue light that is typical of the aurora borealis, which can sometimes be seen from high-northern latitudes.

While the aurora borealis offers a visual display of charged particles from the Sun interacting with Earth’s magnetic field, actually being able to hear the magnetic field generated by Earth or its interaction with solar winds is another matter.

Our magnetic field is largely generated by an ocean of superheated, swirling liquid iron that makes up the outer core. Its movement creates electrical currents, which in turn, generate our continuously changing electromagnetic field.

Launched in 2013, ESA’s trio of Swarm satellites are being used to understand exactly how our magnetic field is generated by measuring precisely the magnetic signals that stem not only from Earth’s core, but also from the mantle, crust and oceans, as well as from the ionosphere and magnetosphere. Swarm is also leading to new insights into weather in space.

More details here.

Image credit: Ben Rider