Listening to Leonids

Bill Kendrick writes: "An interesting article was posted by NASA about reports of people hearing Leonids as they burnt up in the atmosphere. And not 5 minutes later, like you'd expect, but instantly. Apparently this is thanks to very low frequency radio signals given off by the meteors as they burn."

Comments

Sounds like ELF

[Arethan]

...or Extremely Low Frequency for those that have never heard the term before.

The nava used this to communicate with submarines on the other side of the earth by directing ELF signals directly through the earth's core. Saw it on Discovery once. :) I'm not sure if it's still in use today. Usually the government only shows you out-of-service tech on cable networks.

Re:Sounds like ELF

[kikta]

Yes, they are still in use. The primary is somewhere in the upper peninsula of Michigan. It can be received darn near anywhere. However, it transmits VERRRRY SLOOOOWLY. How slowly? I don't know the exact data rate, but to give you an idea, the Navy sends a three-letter code group that directs the sub to do whatever. Oftentimes it is to come to periscope depth, float the antenna, and copy the full message traffic from satelites. Nothing classified here, been public knowledge for years. The reason it's not a big secret is that any non-authorized ELF messages would be pretty easy to detect, and the Navy is surely changing around the groups and their lengths all the time. Watch The Hunt for the Red October and you'll hear them talking about it before they go to periscope depth to get the full message. None of the code groups can do anything wacky, like tell an SSBN (ballistic-missle sub) to nuke China, so the room for someone injecting sinister messages and the damage they could do is very minimal.

Re:MORE DETAILS!

[h8macs]

Here are a couple of good links on ELF.

http://server5550.itd.nrl.navy.mil/projects/haar p/ elf.html

http://www.fas.org/nuke/guide/usa/c3i/elf.htm

Looks like some pretty nifty, and quite dangerous technology.

Amazing that they posted it

[Chairboy]

I'm amazed that they posted it. It seems as if most government agencies (NASA included) are using the 9/11 attacks as an excuse to pull information offline.

Please note that NASA has become increasingly unwilling to divulge information about what happens on the space station. Routine information such as the 'ships log' and audio feeds are no longer shared or available.

I apologize for this off-topic message, but more people should understand that this article, while fascinating, is nothing compared to the reams of important data that is being maliciously sequestered by an organization paid for with tax dollars. For every piece on meteor sounds, there are 10 pages of technical data on spaceflight, human research, and more that is being systematically hidden.

I predict that the information will become available through some type of Lexis-Nexus style pay system in the future so that you can have the privilege of paying for the data twice.

Bread and circuses, my friend. Look at the rest of the story, and make NASA give us what we own.

Re:Oh well...

[NecroPuppy]

How is it once in a lifetime?

The Leonid meteor occurs every 33 years, and take place over several years.

Europe, for instance, is supposed to have the best view next year.

New Scientist had a feature on this earlier...

[weeeeeww]

This was described in a New Scientist feature, first issue this year, and the same explanation was given.

To see the article, you'll need to get a trailist account with their archive. Once you have it, go here, or search for "Sizzling Skies" in the 06 Jan 01 issue.

I Listened to the Leonids

[Sigfried_Blip]

Now this isn't as cool as hearing meteors unaided with my ears. But while I was outside watching the Leonids here in Cupertino, I was also watching and listening to NASA's Meteor-radar with a linux program called baudline. There was a lot of activity that night, about a hit a second. Unfortunately I can't correlate the radar hits with the visuals since I live in California and the meteor radar is in other states (NM TX and AL). Still it was cool.

Right now the meteor radar is getting a hit about every 20 seconds. Sweet, I just saw a 70 second streak with a doppler shift of about 183 Hz. That is screaming at about 17X earth rotation! (If I wasn't so lazy I'd calculate that in MPH or m/s)

How did I do it? I just piped the real-time NASA stream into the standard input (stdin) of baudline, then equalized it with about 10 seconds of quietness, and then watched and listened away. I used this command line:

mpg123 -s http://icecast.msfc.nasa.gov:8000/forward-scat | baudline -stdin -channels 1 -overlap 100 -fftsize 2048 -mem 9 -record -samplerate 22050 -session meteor_radar

If the geocities site for baudline craps out, try again later, or try the mirror site. The downloaded md5sum for baudline_0.87_i686.tar.gz should be 72f949826ac81a461a8b4b5c5551f366

ELF Towers in Annapolis

[cfinegan]

I noticed that one post made mention of some ELF towers in Annapolis. Since I live in Annapolis, and had never heard of this, I got rather curious. After a quick Google search, I came up with a few interesting things:

• Although not as old as NAA, NSS is still in operation on VLF. In fact, it is the oldest continuously operating very low frequency station in the entire world! NSS is located on the small peninsula known as Greenbury Point on the northeastern shore of the Severn River, directly across from the United States Naval Academy at Annapolis, Maryland. Found on http://members.aol.com/k6dc/history.htm. Check this link out for some good info and pics!
• LF (Low Frequency) and VLF (Very Low Frequency) antennas there are no longer used by the Navy and were made available for some experiments by AMRAD ... The Antenna, approximately 400 ft long, is suspended between two towers approximately 300 ft high. Found at http://www.amrad.org/projects/lf/March1999NSS/. More good pics of antennae and info on this link.
• 28. "ELF Communications System Isn't Needed, Might Not Work, GAO Says," Aerospace Daily, March 22, 1979, 107 (cites GAO classified report, The Navy's Strategic Communications System, PSAD-79-48); Seafarer ELF Communications System Final Evaluation Impact Statement for Site Selection and Test Operation (Washington, DC: Dept. of the Navy, December 1977). Found on http://www.ndu.edu/inss/books/milgeo/milgeoch4n.ht ml
• The Coast Guard is establishing a temporary safety zone covering all waters within a 2,000 foot radius of each of three Very Low Frequency (VLF) towers located between Greenbury Point and Possum Point, near Annapolis, Maryland. Potts and Callahan, Inc. will be demolishing the three towers with explosives. This safety zone is intended to restrict maritime traffic in order to protect mariners from the hazards associated with the demolition. http://www.epa.gov/fedrgstr/EPA-IMPACT/1999/Novemb er/Day-29/i30882.htm This was in December, 1999.

So it looks like the Navy did, in fact, have a rather groundbreaking ELF setup back in the day. Unfortunately those antennae seem to be gone now, but hey, technology marches on. Now that I'm reading some of these articles I know exactly which antennae they're talking about, and I do remember noticing that there seemed to suddenly be fewer of them a couple years ago...

Colin Keay

[jmp]

It's good to see that Dr Keay's research has been gained respectability.

I was an undergraduate at the University of Newcastle when he was working on this, and attended a talk he gave on the subject. Perhaps I got it wrong, but I gained the impression that some of his colleagues thought he was wasting his time researching this rather controversial topic.

Respectability is important in the hard sciences, and this must have seemed to some to be more like paranormal psychology than physics. Good on him for sticking to his guns.

You can read more about Geophysical Electrophonics at Colin Keay's home page.

In addition

[wiredog]

In addition to what has already been posted, not every meteor you saw was neccessarily a Leonid. You can see one or two meteors an hour on any night. If it's dark enough.