The Earth is surrounded by a system of magnetic fields, called the magnetosphere, that is necessary for life on Earth. However, the magnetic field is not something we can see or hear in and of itself at all. Remarkably, however, scientists at the Technical University of Denmark have taken magnetic signals measured by the European Space Agency’s Swarm mission and converted them into sounds. For something that protects us, the result is pretty frightening.
Earth’s magnetic field is a complex and dynamic bubble that keeps us safe from harmful cosmic radiation and charged particles carried by the powerful solar winds flowing from the sun. When these particles collide with atoms and molecules — primarily oxygen and nitrogen — in the upper atmosphere, some of the energy in the collisions is converted into the green and blue light that characterizes the aurora borealis. These “Northern Lights” can sometimes be seen from higher northern latitudes.
Although the aurora borealis provide a visual display of charged particles from the sun interacting with the Earth’s magnetic field, it is another matter entirely to be able to hear the magnetic field generated by the earth or its interaction with the solar wind.
Our magnetic field is generated largely by an ocean of superheated, swirling liquid iron that forms the outer core about 3,000 kilometers (1,900 miles) below our feet. Acting as a spinning conductor in a bicycle dynamo, it creates electric currents, which in turn generate our ever-changing electromagnetic field.
ESA trio satellite swarm, launched in 2013, is used to understand how our magnetic field is precisely created by precisely measuring magnetic signals that stem not only from the Earth’s core, but also from the mantle, crust and oceans, as well as from the ionosphere and magnetosphere. Swarm also leads to new insights into space weather.
Claus Nielsen, a musician and project supporter from the Technical University of Denmark explains, “The team used data from ESA’s Swarm satellites, as well as other sources, and used these magnetic signals to manipulate and control the sound representation of the underlying field. The project was certainly a useful exercise in Combining art and science.
It may sound like nightmarish stuff, but, remarkably, this audio clip represents the magnetic field generated by the Earth’s core and its interaction with a solar storm.
“We were able to come up with a very interesting sound system consisting of more than 30 speakers dug into the ground at Solbjerg Square in Copenhagen.
“We set it up so that each speaker represents a different location on Earth and shows how our magnetic field has fluctuated over the past 100,000 years.
“During this week, visitors will be able to hear the amazing bang of our magnetic field – so if you are in Copenhagen, come and check out this unique opportunity.
“The gurgling of the Earth’s magnetic field is accompanied by a representation of a geomagnetic storm caused by a solar flare on November 3, 2011, and it really does look very scary.”
The intent, of course, isn’t to scare people – it’s a weird way of reminding us of the presence of the magnetic field and although the rumble is a little worrisome, the existence of life on Earth depends on it.
Loudspeakers at Solbjerg Square in Copenhagen, Denmark, will broadcast the rumble of the Earth’s magnetic field from October 24-30 at approximately 8 a.m., 1 p.m. and 7 p.m.