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Listening to Leonids

Posted by michael on from the ground-control-to-major-tom dept.

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."

9 of 136 comments (clear)

  1. Sounds like ELF by Arethan · · Score: 4, Informative

    ...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.

    1. Re:Sounds like ELF by kikta · · Score: 4, Informative

      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.

  2. frizzy hair? by Nate+Fox · · Score: 5, Funny

    Simple materials like aluminum foil, thin wires, pine needles -- even dry or frizzy hair -- can intercept and respond to a VLF field.

    I bet Weird Al was having the multimedia show of a lifetime!

    1. Re:frizzy hair? by Raven42rac · · Score: 4, Funny

      Well if were talking about Weird Al, then the abbreviation would have to be changed to UHF, hahahaha, I kill me.

      --
      I hate sigs.
  3. More likely ... by Rosco+P.+Coltrane · · Score: 4, Funny

    One /. reader at Nasa close with his computer close to the antennas saw this earlier post and tried out the program.

    --
    "A door is what a dog is perpetually on the wrong side of" - Ogden Nash
  4. Angry Humpbacks by hubbabubba · · Score: 4, Funny

    I hear this sort of thing really pisses off whales.

    --
    Fried ice cream is a reality. - George Clinton
  5. ELF/VLF listening by yack0 · · Score: 5, Interesting
    This is reminscent of some stuff I initially heard about on an NPR episode of 'Lost and Found Sound' which was a feature they were running in the last year or so.

    Stephen McGreevy, a professor at some college, IIRC, in California has been listening to Aurora Borealis' for years and has actually made recordings of some of the things he's heard and made CD's for retail sale. He also sells receivers to people so they can listen to the earth as well.

    Related links:
    His home page for VLF radio
    The page he wants people to bookmark , cause his current provider bites.
    His second CD
    The VLF receiver page

    --
    -- There is no sig line, only Zuul.
  6. Amazing that they posted it by Chairboy · · Score: 5, Informative

    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.

  7. I Listened to the Leonids by Sigfried_Blip · · Score: 5, Informative

    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