by Staff Writers
Aalto, Finland (SPX) Jul 13, 2012
For the first time, researchers at Aalto University in Finland have located where the sounds associated with the northern lights are created. The auroral sounds that have been described in folktales and by wilderness wanderers are formed about 70 meters above the ground level in the measured case.
Researchers located the sound sources by installing three separate microphones in an observation site where the auroral sounds were recorded. They then compared sounds captured by the microphones and determined the location of the sound source.
The aurora borealis was seen at the observation site. The simultaneous measurements of the geomagnetic disturbances, made by the Finnish Meteorological Institute, showed a typical pattern of the northern lights episodes.
"Our research proved that, during the occurrence of the northern lights, people can hear natural auroral sounds related to what they see. In the past, researchers thought that the aurora borealis was too far away for people to hear the sounds it made.
This is true. 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," said Professor Unto K. Laine from Aalto University.
Details about how the auroral sounds are created are still a mystery. The sounds do not occur regularly when the northern lights are seen.
The recorded, unamplified sounds can be similar to crackles or muffled bangs which last for only a short period of time. Other people who have heard the auroral sounds have described them as distant noise and sputter.
Because of these different descriptions, researchers suspect that there are several mechanisms behind the formation of these auroral sounds. These sounds are so soft that one has to listen very carefully to hear them and to distinguish them from the ambient noise.
The Aalto University researcher's study will be published in the proceedings of the 19th International Congress on Sound and Vibration. The congress is held in Vilnius, Lithuania from 8 to 12 July 2012. Watch a video here.
Aurora research at Aalto University
Solar Science News at SpaceDaily
Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.
HI-C sounding rocket mission has finest mirrors ever made
Greenbelt MD (SPX) Jul 13, 2012
On July 11, NASA scientists will launch into space the highest resolution solar telescope ever to observe the solar corona, the million degree outer solar atmosphere. The instrument, called HI-C for High Resolution Coronal Imager, will fly aboard a Black Brant sounding rocket to be launched from the White Sands Missile Range in New Mexico. The mission will have just 620 seconds for its fli ... read more
|The content herein, unless otherwise known to be public domain, are Copyright 1995-2012 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement|