(meteorobs) [VLF_Group] Chelyabinsk Fireball and electrophonic"noise."
drobnock
drobnock at penn.com
Mon Aug 12 11:13:16 EDT 2013
Hi
The propagation of the single signature created by the meteor's
electromagnetic pulse may not always be received or detected. During the
2001 and 2002 Leonid shower, we observed that as the meteors were
clustered, a greater number of signatures or signals were received, and
as with Prices and others research, we were able to detect a meteors
over the seferic background.
George John Drobnock
Bob Culbertson wrote:
> Thanks for the new web site.A few years ago during the Perseids peak I
> set up a VLF receiver monitoring the Perseids at our local astronomy
> club's grounds. It was the most sphyerics and tweeks I have ever
> heard--no whistlers like I woulf get in the winter at the nordic
> skiing huts. A lightning storm had moved off into eastern Pennsylvania
> that I assumed created the RF VLF signals. VLF RF signals I can not
> hear with my ears thats why I needed the radio which is a NASA INSPIRE
> receiver project radio I built from a kit. I 'heard' nothing from the
> Perseids this morning from 0800 to 0830 UTC but visually saw 5
> meteors. The first meteor came from the Nnortheast straight down as I
> was positioned directly towards the radiant. From the first attachment
> shows the Perseids center of the 4 pink dots was at a 60 degrees
> elevation and at 45 degrees azimuth Northeast. Realizing that meteor
> radio propagation propagation direction is at right angles to the
> Perseid's radiant's azimuth and the center of meteor trails I
> repositioned myself facing just Southeast 135 degrees and saw 4 more
> meteors. The center of these 4 meteor trails was about 60 degrees in
> elevation. Clouds moved in and prevented any observation of the other
> right angle propagation direction of the northwest 315 degrees
> azimuth.Not a bad visual observation for someone needing a cataract
> operation. The second attachment is from the Canadian meteor radar
> site that is close to me.The daytime XRI Xi Oroinids have risen before
> the Sun (left-east)-present Perseids(PER) activity going into the
> color white to pink looks equivalent to the present Southern Delta
> Aquarids (SDA) activity. I thought the Perseids would show more
> activity. Compare the Perseid peak today of the 2nd attachment with
> the Southern Delta Aquarid peak July 30 2013 of the last attachment.
> The SDA meteors are so intense as to be colored white to pink, then
> red, then yellow and finally green as we get to the center of the
> radiant. The CAP or alpha Capricornids also peak July 30th were about
> as intense then as our present Perseids are now. Interesting since my
> study with meteors involves meteor induced Sporadic E for amateur
> radio. It should be apparent that the Southern Delta Aquarids at its
> peak would yield better meteor induced Sporadic E than our present
> Perseid meteor shower. Bob
>
> On Sun, Aug 11, 2013 at 2:31 PM, drobnock <drobnock at penn.com> wrote:
>
> Hi
> With the current interest in the Perseids, I was reviewing
> older meteorobs post. Your was interesting. The information
> presented about Stetson, 1934, Earth, Radio, and the Stars
> is similar to G. Hawkins (1958). The emission of
> electromagnetic noise from a meteor can be found back to the
> early days of radio or wireless, Udden, 1917, Texas Meteor,
> Univ of Texas Bulletin no. 1772,45-47 and Nininger, 1934,
> Sound from ether waves., Pop. Astronomy, 47, 97-99. For a
> more intensive bibo. see works of C. Keay.
>
> George John Drobnock
>
>
> Please see:
> http://adsabs.harvard.edu/full/2002JIMO...30..152D
> RE: Title: VFL (sic) Signatures from non-fireball meteors
> -- Observations from the 2001 Leonid shower
> Authors: Drobnock, G. J.
> Journal: WGN, Journal of the International Meteor
> Organization, vol. 30, no. 5, p. 152-156
>
> George John Drobnock
>
> Bob Culbertson wrote:
>
> > This passage of a brilliant meteor and an extraneous sound
> > in the receiving circuit has been known since 1921. Page
> > 225 of the first attachment.The second attachment page 226
> > at the top; with passage of a meteor a sharp hiss that
> > began and ended with the meteor.Note the frequency here is
> > not VHF or even HF but rather at LF with a CW coast
> > station transmitting in Bordeaux France observed in
> > Seabrook Beach New Hampshire.Last attachment may help
> > explain the propagation mode; Meteor Induced Sporadic
> > E.Using 'Radio-Eyes' and going back to August 29, 1921, I
> > found the propagation direction did not come from the
> > Perseids as mentioned here but rather the kappa Cygnids
> > that actually passed through the Perseids on their way
> > West.Amazing the things we can do today. Equally amazing
> > is what we have lost.Bob WA3YGQ
> >
> > On Wed, Apr 3, 2013 at 12:00 AM, Cliff
> > Sojourner <cls at employees.org> wrote:
> >
> >
> > my friend is an avid astronomer and chases
> > eclipses and meteor showers
> > and such...
> >
> > he assures me there is a sound, a hissing sound,
> > from the brightest
> > meteors. he likes to go to the quietest place
> > in the Sierra Nevadas
> > during the busiest showers, watch and
> > photograph, and especially
> > listen. He resents getting old, the sound is
> > elusive now...
> >
> > Cliff K6CLS CM87
> >
> > On 2013-04-02 08:09, drobnock wrote:
> > > If this was presented earlier, sorry.
> > >
> > > On a forum identified as Nasa Space Flight
> > .com there was a question
> > > asked about the Chelyabinsk Fireball and
> > electrophonic "noise."
> > > According to the article presented from
> > Russia, 27 individuals heard a
> > > hissing during the event. Note the question
> > marks are part of the
> > > Russian Text. with rough translation from an
> > on line survey about the
> > > event.
> > >
> > > George John Drobnock
> > >
> > > Question posted 2/17/2013 on the
> > Nasaspaceflight.com.
> > > ""I would also be very interested in
> > eyewitness reports of electrophonic
> > > sound PRIOR to the acoustic shock -- that is,
> > during the brightest
> > > flaring of the fireball. This is a
> > at-long-last well-established effect
> > > of plasma-generated radio noise coupling into
> > near-observer physical
> > > objects and creating a hissing or whooshing
> > sound. It occurs simo with
> > > the visual flares, seems to come from 'all
> > around' [not from above], has
> > > been reported for centuries by some bright
> > fireball witnesses and
> > > pooh-poohed by scientists until work by Colin
> > Keay and others
> > > established its validity.""
> > >
> > > Later Response posted.
> > >
> > > http://www.chel-meteorit.youini.ru/
> > > Approximate translation: Profile observations
> > falling meteorite
> > > Chelyabinsk February 15, 2013
> > >
> > >
> > http://chelyabinsk.ru/text/newsline/625214.html
> > > is titled
> > > **?????, ???????????? ??? ???????????,
> > ???????? «????????»**
> > > **Chelyabinsk Fireball turned out to be
> > "sounding"**
> > >
> > > ""Article says 27 eyewitnesses independently
> > noted that they heard weak
> > > but clear hissing sounds DURING the flight.
> > Many of them compared the
> > > sound with "Bengal sparkler" (Popular in
> > Russia type of hand-held light
> > > firework) and noted that could not determine
> > neither the source of
> > > hissing nor direction it came from.
> > >
> > > This information was gathered via
> > internet-form for eyewitness reports
> > > here:
> > > http://www.chel-meteorit.youini.ru/
> > > I'd like to note that there is no direct
> > question in the form about this
> > > effect, the respondents were NOT prompted to
> > describe it, they all did
> > > it in "Additional Comments" field.""
> > >
> > >
> > http://chelyabinsk.ru/text/newsline/625214.html
> > >
> > http://forum.nasaspaceflight.com/index.php?topic=31118.465
> >
> > >
> > >
> >
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