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Recording of mysterious meteor sounds

Joined by the International Leonid Watch - Croatia (ILWC) project, a group of scientists presented the first instrumental detection of elusive electrophonic meteor sounds. In November 1998, the researchers from the Croatian Physical Society and the University of Kentucky organized an expedition to Mongolia to observe the anticipated Leonid meteor shower and shed some light on the phenomenon. The complete data analysis revealed two electrophonic sounds that provided several important clues about the nature of this longstanding astronomical mystery. The paper about these results will appear in the Journal of Geophysical Research (more...).

More information:

ILWC FEATURED BY:

News release (complete text)

Preprint of the article " Instrumental recording of electrophonic sounds from Leonid fireballs": (PDF format, postscript format)

Visit our Picture Gallery from Mongolia.

Video of the first electrophonic meteor. Meteor's  maximum brightness is -6.5m. The appearence of the electrophonic sound is marked by the letter "E" in the video. At that moment, the meteor had brightness of -1m and altitude is calculated to be ~ 100km (70miles). The sound is of very low frequency and resembles a deep "pop". The instrumental noise is digitally suppresed fof clarity.  Download video file (avi format, size: 1.3 Mbyte)

Audio of the second electrophonic meteor. The meteor's  maximum brightness was estimated to be  -12m. The meteor was not recorded on video, but 6 observers saw it and reported hearing an electrophonc sounds. The sound is of very low frequency and resembles a deep "pop".  Download audio file (avi format, size: 0.3 Mbyte)

An introductory page to the phenomenon of electrophonic sounds, at GEFS project webpage.

Contact:

Slaven Garaj
Institute of Nuclear Engineering (IGA)
Department of Physics
Swiss Federal Institute of Technology Lausanne (EPFL)
CH-1015 Lausanne
Tel.: +41 (21) 693 4337
Fax: +41 (21) 693 4461
e-mail: slaven.garaj@epfl.ch

 

Full list publications and conference reports:

  1. S. Garaj: Leonid meteor storm 1998 - ELF/VLF measurements, International Symposium on Astrophysics Research and Science Education 1998., Vatican Observatory, Ed. C.D. Impley (The University of Notre Dame Press, 1999).

  2. Vinkovic, D., Garaj, S., Zgrablic, G., Gradecak, S., Kovacic, D., Biliskov, N., Grbac, N., Andreic, Z. "ELF/VLF emission and electrophonic sounds from Leonids identified", Leonid MAC Workshop, NASA Ames Research Center, CA, April 12-15, 1999.

  3. G. Zgrablic, S. Garaj, D. Vinkovic, D. Kovacic, S. Gradecak, N. Biliskov, N. Grbac, Z. Andreic : Electrophonic sounds and VLF electromagnetic radiation from meteors (ILW Croatia project), Croatian Physical Society Conference, Zagreb (Dec. 1-3, 1999).

  4. Garaj, S., Vinkovic, D., Zgrablic, G., Kovacic, D., Gradecak, S., Biliskov, N., Grbac, N. Andreic, Z: "Observational detection of meteor-produced VLF electromagnetic radiation" FIZIKA 8, 91-98, (1999).(download PDF)

  5. D. Vinkovic, Z. Andreic, S. Garaj, D. Kovacic, M. Mladinov, G. Zgrablic: Global Electrophonic Fireball Survey, WGN  28, 48-53 (2000) (download PDF)

  6. Goran Zgrablic, Dejan Vinkovic, Silvija Gradecak, Damir Kovacic, Nikola Biliskov, Neven Grbac, Zeljko Andreic & Slaven Garaj: Instrumental recording of electrophonic sounds from Leonid fireballs, accepted for publication in J. Geophys. Res. (download preprint)

Further Work:

Systematic collection of witness reports of electrophonic sounds, through the project: Global Electrophonic Fireball Survey, at University of Kentucky.

 

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