The MAARBLE “Sounds of Space” Musical Composition ContestPlanet Earth is a natural source of radio waves, which surround us all the time. Although most of these waves are in the acoustic frequency range, they are not audible by humans. They are electromagnetic waves and not acoustic ones. We could “hear” them if we had radio antennas instead of ears. Radio waves can be detected by our ears if we convert them to sound waves, by using a very low frequency (VLF) receiver. A VLF receiver consists of an antenna and a radio amplifier, and it is sensitive to radio waves. After converting electromagnetic (radio) waves into acoustic (sound) waves, with the same frequency, the sounds produced by our planet can be “heard”. These sounds correspond to several types of radio emissions propagating in the Earth’s atmosphere, ionosphere and magnetosphere. The way these waves sound, when played through an audio system, defines their name: sferics, tweeks, whistlers, chorus, and hiss. We also call them “Earth Songs”. The MAARBLE contest of musical composition combines scientific and artistic ways of thinking, i.e. the Art of Music and Space Science. The musical contest is an original idea to provide scientific information to the public, inviting people to “feel” the science and to think about art. The MAARBLE project invites composers from all EU countries, USA and Canada, to take part in the MAARBLE musical contest. The leading concept is to use the natural sounds of the Earth’s magnetosphere in order to compose electroacoustic music. The relevant Notes for Guidance and the Application Form are available below.
ANNOUNCEMENT OF WINNERS OF THE MAARBLE “SOUNDS OF SPACE” MUSICAL COMPOSITION CONTEST
We are pleased to announce the successful completion of the MAARBLE Musical Composition Contest. The contest was oversubscribed by a factor of 19 (we received in total 55 applications from 17 countries). The Selection Committee* met on June 14 for the judging of applications and was very pleased with the overall quality of the submitted compositions, which made the selection of winners a very difficult task. First Prize (award of 1500 €): “Breathing Underwater” by Otto Wanke (Czech Republic)
AWARD CEREMONY - Rodon Municipal Theater
|
Samples and descriptions of characteristic space sounds
Sferics
The shortcut for “atmospherics” because they are emitted by lighting strokes. They propagate great distances round the Earth bouncing between Earth’s surface and the ionosphere, from 90km above the ground to thousands of kilometers in altitude. Their dynamic spectra are characterized by vertical lines indicating the simultaneous arrival of all radio frequencies.
Sample of audio file here:
Credit: NASA INSPIRE
Tweeks
Are sferics that travel farther. Their dynamic spectra illustrates that high frequencies arrive first, followed by the lower ones. The sound they produce is characterized by the non simultaneous arrival of the frequencies they consist of.
Credit: NASA INSPIRE
Whistlers
They originate from thunderstorms or meteorites, or after earthquakes. They propagate at great distances between ground sources and various points in the ionosphere and overlying magnetosphere. They are much more dispersed than the tweeks. They interact with plasma particles in the radiation belts.
Whistler that propagated along geomagnetic-field-aligned paths from a lightning flash in the northern
hemisphere to Palmer Station, Antarctica (by the Stanford VLF group)
Credit: NASA INSPIRE
Dawn Chorus
Chorus waves are generated near the magnetic equator outside the plasmasphere, occur over a broad frequency range, from hundreds of Hz up to several kHz and sound like birds singing when played through an audio converter. They interact with high energy electrons in the radiation belts and accelerate them during geomagnetic storms. The accelerated electrons can become dangerous for both satellites (since they can damage electronic equipment) and astronauts. For this reason they are called “killer electrons”. Chorus emissions are observed over a wide range of local times, having a peak near local dawn. Chorus intensity increases during magnetospheric substorms, periods during which the aurora is observed in high latitudes.
Credit: ESA
Hiss
Plasmaspheric hiss are low-frequency radio waves. Electrons in the outer radiation belt can extract energy from chorus waves to reach near-light speed and become dangerous for human activity in near space environment. When this happens, the chorus evolves into another type of radio wave called hiss. Hiss deflects the speedy particles into Earth's upper atmosphere, where they lose energy and are absorbed when they hit atoms and molecules there.
Sample of audio file here:
Credit: University of Iowa
Read more:
http://www.nasa.gov/mission_pages/themis/news/themis_singing_electrons.html
http://science.nasa.gov/science-news/science-at-nasa/2012/28sep_earthsong/
http://science.nasa.gov/science-news/science-at-nasa/2001/ast19jan_1/
Sample of sounds here:
http://www-pw.physics.uiowa.edu/plasma-wave/istp/polar/magnetosound.html
http://www.spaceweather.com/glossary/inspire.html
http://theinspireproject.org/default.asp?contentID=17
