A group of high school students recently discovered the low-frequency echoes of a solar storm in space, and it turns out that Earth’s magnetic field is crawling with similar sounds.
The Alien franchise tagline didn’t lie: in space, no one can hear you scream. No one can hear laser weapons firing or damaged starships exploding, either. Sound waves happen when a moving object pushes on nearby air molecules, which in turn push against their neighbors, creating a ripple of moving air (or water, or other material). In a vacuum, there are no molecules to move and create sound waves.
But parts of space aren’t a perfect vacuum, and if the length of the wave is long enough, it can move through sparse, widely-spaced molecules. The sounds rippling through our planet’s magnetic field are much too low for a human ear to hear, but physicist Martin Archer and his colleagues at Queen Mary University of London sped up the recordings from NOAA’s Geostationary Operational Environmental Satellite, or GOES, into the audible range.