..August 10 through August 13, with peak activity August 12 around 1 A.M. 'til dawn:
The Perseid Meteor Shower.
This year the Moon will be excusing herself early enough to provide us Earthlings with an unfettered view of the nocturnal sky, weather permitting.
While the media will tell you that during the peak you can expect 60 to 100 meteors per hour to be visible, don't count on it. Most are small and only visible for a second or two. But it's still worth the time spent, and it's free. You might even get lucky and catch a spectacular entry that's close enough to hear. I'm gettin' goose-bumps..
I prefer a supine position in soft grass to lessen neck fatigue. 12 year old Scotch is a necessity to sharpen the senses, but 8 year old spirits will work almost as well. Ice is optional.
good luck
Not to be a party pooper, but it's an auditory illusion to think you can hear a meteorite entering the thin atmosphere 150 miles over your head.
First, there's the (varying) speed of sound to contend with. Even if you could hear it, the sound would take minutes to reach you from that far away and hence, you wouldn't sense it concurrently with the 5-second flash of light.
Second, I doubt I could hear the boom of a hydrogen bomb 150 miles away, much less the high frequency 'hissing' sound I would have swore I heard when I saw that meteor flash. That old inverse square law still applies.
I used to think I could hear meteorites and even the Northern Lights, but the physics finally convinced me otherwise.
Sometimes It Is Just A Faint Puff Of Light
Especially when you are concentrating on one area of sky, your peripheral vision says it is over here. Turn and it is already done.
I prefer a laid back Adirondack, I am too old to be on the ground. Well actually not too old to be on the ground but too old and stiff by the time I am ready to get up.
The best years of viewing were when we were first married up until the kids were 10-12. We would take a week in Canada. Night fishing and meteors, what a great way to relax. Next best way was Scouting campfires and tentless camping under the stars.
Paul in PA
:good:
> Not to be a party pooper, but it's an auditory illusion to think you can hear a meteorite entering the thin atmosphere 150 miles over your head.
Actually, you can hear meteors as they enter the atmosphere. The mechanism is a bit unusual. Their glowing trails through the atmosphere give off very low frequency radio signals which travel to the observer's position at the speed of light and can induce vibrations in objects around the observer such as eyeglass frames, pine needles, or even hair. Those are what produce the hiss one hears.
have fun.. use to do it..
but night sky viewing sucks here in the summer because of the humidity.
everything is filtered by the humidity and any ambient light adds to the obfuscation.
Sorry Kent, even though your source is good I'm not buying it. Even though I've "heard" it myself, Keay's paper seems an exercise in question begging, the mechanism is ill-defined, and the corroboration is scant. As such, I'll have to wait for something more definitive than anecdotes, a vaguely plausible explanation, and a single paper reporting an instrument recording of the hypothetical effect.
> Sorry Kent, even though your source is good I'm not buying it. Even though I've "heard" it myself, Keay's paper seems an exercise in question begging, the mechanism is ill-defined, and the corroboration is scant. As such, I'll have to wait for something more definitive than anecdotes, a vaguely plausible explanation, and a single paper reporting an instrument recording of the hypothetical effect.
Okay, so you admit that you personally have observed the phenomenon (as I have) and you think instead that you just imagined hearing anything because you don't have any explanation for how you could possibly have heard anything? That seems to me to be a fundamental error to ignore an observation because one can't explain it.
The simplest mechanism I would think is that cochlear hairs are induced to vibrate by the very low-frequency RF emissions from meteors entering the atmosphere.
> Okay, so you admit that you personally have observed the phenomenon (as I have) and you think instead that you just imagined hearing anything because you don't have any explanation for how you could possibly have heard anything? That seems to me to be a fundamental error to ignore an observation because one can't explain it.
I explained why I'm not satisfied with Keay's paper. It's weak because assumes a conclusion a priori, and it hasn't been satisfactorily corroborated. This is not 'settled science' by any stretch of the imagination.
As to cochlear vibrations - were that indeed the mechanism, we would be able to 'hear' all sorts of radio frequencies on a regular basis. But we don't.
To restate: If Leay's explanation has a strong basis in fact, rigorous observations of meteor 'sounds' should be easily repeatable. But they're evidently not. So I remain skeptical.
> As to cochlear vibrations - were that indeed the mechanism, we would be able to 'hear' all sorts of radio frequencies on a regular basis. But we don't.
How common do you think strong, very low frequency RF signals are? Isn't that exactly what is unusual about the RF emissions from meteors?
> How common do you think strong, very low frequency RF signals are? Isn't that exactly what is unusual about the RF emissions from meteors?
I think VLF transmissions are fairly common. Certainly more common than visible meteorites, yet we don't hear them.
The Russians still use ELF to communicate with submarines worldwide. I don't hear them.
Are you proposing that meteorites and aurora are the only things capable of producing the sort of VLF electromagnetism humans can "hear"?
> I think VLF transmissions are fairly common. Certainly more common than visible meteorites, yet we don't hear them.
> The Russians still use ELF to communicate with submarines worldwide. I don't hear them.
I doubt very much that they are of an even remotely similar order of magnitude of signal strength to what a Leonid fireball generates.
> I doubt very much that they are of an even remotely similar order of magnitude of signal strength to what a Leonid fireball generates.
>
It takes an enormous amount of wattage (megawatts to gigawatts) to transmit ELF and a huge grounding mass, which is one of the reasons the US no longer uses ELF to signal subs to surface and receive messages on higher bandwidth freqs. - the infrastructure is too expensive, and the information transmits very slowly over ELF.
While a meteorite may have plenty of kinetic energy to convert into electromagnetic energy, it would splatter all over the RF spectrum and not necessarily limit itself to VLF/ULF sans a mechanism. Moreover, a mechanism for converting lightspeed EM to audible freqs needs to be pinpointed to something less conjectural than ear hair.
> Recording of Sounds from Leonid Meteors
"Simultaneous measurements of electromagnetic ELF/VLF radiation above 500 Hz did not reveal any signal correlated to the electrophonic event. The lack of signal was explained by the low frequency of electrophones."
Shame they didn't have the equipment to sense ELF/VLF below 500 Hz and corroborate the anecdotal evidence. Also, since 2001 these observations have not been replicated.
I'd like for there to be a good explanation for what I've 'heard', but I'll have to wait until the science is a little less speculative.
> I'd like for there to be a good explanation for what I've 'heard', but I'll have to wait until the science is a little less speculative.
Well, if you are now actually convinced that you actually did hear a sound attributable to a meteor, I'm happy that you are willing to begin with observations instead of explanations. :>
Youtube video of russian meteor w/ sound
you hear the sound 31 seconds into the video. Not ELF, it's in the normal audio range of human hearing (and dog hearing)
the experts recommend ;listening for a full minute after seeing the fireball to hear the associated sound.
Thanks Kent. I'm not sure I'm convinced I've heard meteors and aurora. It's more of a fleeting thing that's too easy to enlarge in retrospect. That's probably why I don't want to settle for anything less than solid science.
That's what I like about you - you don't appear to be one to shortcut the fundamentals, no matter how convenient or remunerative it may be. I esteem that quality in a person.
Youtube video of russian meteor w/ sound
That seems a lot closer to the observer than the Perseids we've been discussing, and can almost certainly be accounted for with standard acoustics.
> Thanks Kent. I'm not sure I'm convinced I've heard meteors and aurora. It's more of a fleeting thing that's too easy to enlarge in retrospect. That's probably why I don't want to settle for anything less than solid science.
Yes, the experimental apparatus that the scientists used was interesting. They had pairs of observers listening for the sound of a meteor in a remote, quiet setting, an open microphone recording, and another microphone of the same design acoustically isolated in a box, and all synchronized with a video recorder to within a few thousandths of a second.
The fact that the acoustically-isolated microphone recorded a signal and that it arrived slightly before the video showed the meteor reaching maximum brightness indicated the near-instantaneous nature of the source, which pretty much has to mean an RF signal of some low frequency similar to that of the recording.
Youtube video of russian meteor w/ sound
> That seems a lot closer to the observer than the Perseids we've been discussing, and can almost certainly be accounted for with standard acoustics.
Yes, the Perseids are generally pretty small and not usually any fireballs. Just saw my first Perseid a few minutes ago though and it was a pretty good one. Brighter than any of the stars.
> Yes, the experimental apparatus that the scientists used was interesting. They had pairs of observers listening for the sound of a meteor in a remote, quiet setting, an open microphone recording, and another microphone of the same design acoustically isolated in a box, and all synchronized with a video recorder to within a few thousandths of a second.
>
> The fact that the acoustically-isolated microphone recorded a signal and that it arrived slightly before the video showed the meteor reaching maximum brightness indicated the near-instantaneous nature of the source, which pretty much has to mean an RF signal of some low frequency similar to that of the recording.
From the abstract:
"... We show
that physical characteristics of Leonid electrophones cannot be completely explained by
existing theories [like Leahy's] and that further theoretical refinement and observational work is needed.
Finally, we tentatively suggest the possibility of stronger than expected coupling of
fireballs with atmospheric charge dynamics and ionosphere." -- Zgrablic, et al
Aside from agreeing with my previous points, this seems to leave the door open to quantum and other strange and wonderful electric effects...it'll be interesting to see when someone finally figures it out. B-)
