The Earth’s magnetic field is something that many of us may take for granted, since it’s not something we can see, feel or hear. That last point has now changed though, as scientists and musicians have worked together to convert magnetic field data into sound – with spooky results.
The molten iron swirling around in the planet’s outer core generates electrical currents that in turn produce a huge electromagnetic field that engulfs the Earth. This bubble serves a protective role, repelling cosmic radiation and charged particles from space, and particularly from the Sun.
It does this important job thanklessly in the background – in fact, the only way most people see it in action is through the aurora. But now, researchers have given us the soundtrack to this light show. The key was the Swarm satellites, which have been monitoring the Earth’s magnetic field for almost a decade.
“The team used data from ESA’s Swarm satellites, as well as other sources, and used these magnetic signals to manipulate and control a sonic representation of the core field,” said Klaus Nielsen, a musician involved with the project. “The project has certainly been a rewarding exercise in bringing art and science together.”
The clip, which you can hear above, captures the magnetic field as well as a solar storm that struck in November 2011. And the end result sounds really eerie – it starts with some deep scrabbling sounds, almost like creaking wood on a ship, with some higher pitched metallic plinks and a low rumble like an earthquake underneath. Soon the storm kicks in, bringing what sounds like a rattlesnake tail. At some points it sounds like heavy creatures moving through the forest, while at others you might swear you can almost hear voices.
While the soundscape might make some good ambience for a Halloween party, the team plans to play it for the public in Denmark between October 24 and 30, several sessions per day.
“We gained access to a very interesting sound system consisting of over 30 loudspeakers dug into the ground at the Solbjerg Square in Copenhagen,” said Nielsen. “We have set it up so that each speaker represents a different location on Earth and demonstrates how our magnetic field has fluctuated over the last 100,000 years.”
Converting data to sound – a process called sonification – is an intriguing way to present information. In recent years it’s been used to listen in on cosmic objects like nebulae and clusters, spacecraft telemetry data, and protons colliding inside a particle accelerator.
Source: ESA