Mysterious Sounds Made by the Aurora Borealis

by Nancy Atkinson on July 9, 2012

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Astrophoto: Swirling Aurora by Jason Ahrns
Caption: Swirling Aurora. Image Credit: Jason Ahrns

There have been legends and folktales about sounds associated with auroae, but most accounts were summarily dismissed as imagination or illusion. But researchers in Finland set up microphones in conjunction with an aurora observation site and over the past 12 years captured a “clapping” sound that occurs at certain times when the Northern Lights are ablaze in the sky.

“In the past, researchers thought that the aurora borealis was too far away for people to hear the sounds it made,” said Unto K. Laine from Aalto University in Finland. “However, our research proves that the source of the sounds that are associated with the aurora borealis we see is likely caused by the same energetic particles from the Sun that create the northern lights far away in the sky. These particles or the geomagnetic disturbance produced by them seem to create sound much closer to the ground.”

The researchers installed three separate microphones and were able to record the sounds, which sound similar to crackles or muffled bangs which last for only a short period of time.

They then compared the recordings and determined the location of the sound source was about 70 meters (230 feet) above ground.

They made the recordings along with simultaneous measurements of the geomagnetic disturbances by the Finnish Meteorological Institute. The sounds did not always occur, but when they did, the measurements showed the aurorae were showed of a typical pattern, according the geomagnetic measurements.

The team said that it is not yet scientifically proven that the “clap” sound is related to the aurora borealis, but similar events have been detected only during times of high geomagnetic activity.

“Our research proved that, during the occurrence of the northern lights, people can hear natural auroral sounds related to what they see,” said Laine.
The sounds are quite soft, so one has to listen very carefully to hear them and to distinguish them from the ambient noise, the team said.

Details about how the auroral sounds are created are still a mystery, Laine said. The descriptions of the sounds vary from claps, to distant noise or sputter, and the So, because of these different descriptions, researchers suspect that there are may be several mechanisms behind the formation of these auroral sounds.

Find more information on these mysterious sounds on the team’s website, Auroral Acoustics

Source: Eurekalert

About 

Nancy Atkinson is Universe Today's Senior Editor. She also works with Astronomy Cast, and is a NASA/JPL Solar System Ambassador.

gopher652003 July 10, 2012 at 2:28 AM

I’ve seen other non-conclusive research on this before, and they came to the same preliminary conclusion.

I’ve never heard this myself. Sounds like it would be interesting:).

Mark Fesco July 10, 2012 at 4:53 AM

I stayed the winter in the Northwest Territory of Canada a couple years ago and was told that sometimes they sounded like “rice crispies.” I didn’t believe it until I heard it for myself. I only heard it once but it was true. Sounded like crackling.

SJStar July 10, 2012 at 7:00 AM

… or the kids ruffling of the cellophane.

Chicago Astronomer July 10, 2012 at 6:19 AM

Same for meteors.

“Professionals” in the field state that meteors are too far up in the atmosphere for the sound waves to be created.

Many, including myself, have heard the crackle of larger meteors break up.

Torbjörn Larsson July 10, 2012 at 8:40 PM

Sounds intriguing.

[... aaand gopher 652003 was there before me. Note to self: read thread first, respond later.]

DarkGnat July 10, 2012 at 9:49 PM

I wonder if the phenomenon is like thunder, but less powerful. Could air simply be rapidly expanding or contracting if conditions are right?

Sarv-NASA Incorporated July 11, 2012 at 3:05 PM

AR 1520 is just a sign of the sun trying to rig out some HF/FM radio transmitters….. and AR 1472 was a sign of a little business deal in progress…. however, sensing bad vibes floating in from everywhere…. he backed out of the deal….
and the flares & CMEs (there have not been many real CMEs in the recent past, with juices squirting out on eit304 images lately)…… and the sun is now trying to control his anger, and you don’t see many filaments there…. however, unnecessary useless alien space-invaders are being warned to stay away….. and the useless editors who copy & paste these useless reports are advised to refrain from publishing these freak reports….. or be ready to be sued for defamation…..
Space agencies too are advised not to play these stupid HD tricks anymore….. and find jobs elsewhere in chinese factories……
Now that you too know about the existence of the sun as a man another living somewhere….. we expect everyone to just shut up……

Sarv-NASA Incorporated July 11, 2012 at 3:17 PM

Most people who connect to others…. even in imagination….. do end up teleporting themselves as little beings in the astral….. Maybe someone heard the crackling sounds from the radio receivers…..

some of our friends did report hearing the test tones (400 Hz – 3000 Hz) in their ears….. when he was working with the radio-communication test sets….

And they have reported hearing some HF noises, when they operate a vacuum cleaner……

And don’t be afraid of these signs, which are visible everywhere….. space agencies have finally offered territories & settlement to the sun to send him away from conflicting uncivilized humans….. so you don’t have to see these signs….

And I forgot to mention….. I am not aware, if the sun himself or anyone else has authorized anyone to monitor his star…. and issue these reports…. consider it as a warning, coz we have witnessed people suffering…. who ever had a conflict with the sun…..

Okay folks we are now busy rigging up a noisy HF pirate home-brew transmitter, with low frequency stability…. and will broadcast the sounds in our workshops live soon…. soon we might tell you the frequencies for you to tune into….. and it is going to be QRP….

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