Report from the ISSI Team #546 Magnetohydrodynamic Surface Waves at Earth’s Magnetosphere (and Beyond) led by Martin Archer and Katariina Nykyri
Earth’s magnetic environment is filled with a symphony of sound that we cannot hear. All around our planet, ultralow-frequency waves compose a cacophonous operetta portraying the dramatic relationship between Earth and the Sun. Now, a new citizen science project called HARP – or Heliophysics Audified: Resonances in Plasmas – has turned those once-unheard waves into audible whistles, crunches, and whooshes. Early tests have already made surprising finds, and citizen scientists can join the journey of sonic space exploration to decipher the cosmic vibrations that help sing the song of the Sun and Earth.
When solar plasma strikes Earth, it causes the magnetic field lines and plasma around Earth to vibrate like the plucked strings of a harp, producing ultralow-frequency waves. In 2007, NASA launched five satellites to fly through Earth’s magnetic “harp” – its magnetosphere – as part of the THEMIS mission. Since then, THEMIS has been gathering a bounty of information about plasma waves across Earth’s magnetosphere.
The frequencies of the waves THEMIS measures are too low for our ears to hear, however. So the HARP team sped them up to convert them to audible sound. By using an interactive tool developed by the team, you can listen to these waves and pick out interesting features you hear in the sounds. Humans are often better at picking out interesting wave patterns by ear than by eye – and can even do better than computers at identifying complex patterns that emerge during extreme solar events.
To start exploring these sounds, visit the HARP website.