Have you heard a meteor / meteorite?

Moon (James) · #1 04-08-2009, 09:04 PM

I've seen plenty, but never heard any sounds at all.
To see a huge fireball without any sounds in the dead of night seems really strange.

They **must** make some noise, I guess I've never been close enough. Has anyone ever heard one?

Any IIS members out there lucky enough to recovered a 'fall'?? I think this would really be a great experience, so long as it lands in my garden and not on the house!

leon · #2 04-08-2009, 09:06 PM

James I have seen plenty as well, but not to date have I heard a sound, I think one would be lucky indeed to get audio/visual.

Leon

Blue Skies (Jacquie) · #3 04-08-2009, 09:17 PM

I've heard and experienced window-rattling sonic booms from large bolides that have come in over Perth in the past, but I've never heard the hissing sound that is sometimes reported with them. They've got to be really big to make a sonic boom, and even then you need to be just about right under them to hear it.

MrB (Simon) · #4 04-08-2009, 09:29 PM

I missed visually witnessing one of the the ones Jacquie is talking about by only a min or two. It was huge and I was kicking myself.
I was outside stretching my legs and looking up for a few mins, then decided to head to bed.
Just got my head on the pillow when I heard a hissing-crackling sound.
The hissing-crackling sound and the blue-green flickering light at first had me thinking it was an electrical fault....... untill I realised that the light was illuminating everything all the way to the horizon. Still didn't click to what it was 'till I heard the sonic boom some time later which was soo deep it was almost inaudible, but it sure rattled windows. Kinda like very distant thunder.
That was around, '95 or '96 or something.
A similar thing happened in '87-ish, no hissing but a big sonic boom and rattling windows.
About 1990-ish my brother, a mate and myself witnessed a huge daytime bolide that split into two. No sound tho.

space oddity · #5 04-08-2009, 10:29 PM

Several years ago at the ASNSW star party, several of us saw a bolide break up into 3 pieces at what appeared to be not that far above our heads. I know now that it would have been miles up. Despite being not too crash hot hearing wise(deaf as a doornail), I heard such a hissing crackling sound, a bit like fireworks. Pity I did not know as much about meteorites then as I do now, as I would have been tickled pink knowing I was one of the minority who could hear the electrophonic hiss. Apparently, as the bolide breaks up it emits electromagnetic radiation which then gets retransmitted to audible sounds by nearby metallic objects.On this occasion, there were scores of telescopes in the area.The bolide shows up on one of my wide field star trail photos I was taking at the time-does not look as spectacular on the film as it should, as the lens was an 8mm f/4 circular fisheye.

Moon (James) · #6 04-08-2009, 10:54 PM

Great stories. It gives me hope that one day I might have a close encounter.

seanliddelow (Sean) · #7 04-08-2009, 11:31 PM

Quote:

Originally Posted by MrB

I missed visually witnessing one of the the ones Jacquie is talking about by only a min or two. It was huge and I was kicking myself.
I was outside stretching my legs and looking up for a few mins, then decided to head to bed.
Just got my head on the pillow when I heard a hissing-crackling sound.
The hissing-crackling sound and the blue-green flickering light at first had me thinking it was an electrical fault....... untill I realised that the light was illuminating everything all the way to the horizon. Still didn't click to what it was 'till I heard the sonic boom some time later which was soo deep it was almost inaudible, but it sure rattled windows. Kinda like very distant thunder.
That was around, '95 or '96 or something.
A similar thing happened in '87-ish, no hissing but a big sonic boom and rattling windows.
About 1990-ish my brother, a mate and myself witnessed a huge daytime bolide that split into two. No sound tho.

I was born around then (1995) probably woke me up as a baby!

seanliddelow (Sean) · #8 04-08-2009, 11:35 PM

Earlier this year i was in my school gym and i heard a massive explosion. I dont think this was thunder because there wasnt any thunder before or after that. It was followed by a flash. It could have been lightning but i think that is unlikely. Do bolides flash white? Or did i see lightning? It was cloudy so no meteor could have been seen. It was heard a kilometer away.

sheeny (Al) · #9 05-08-2009, 07:08 AM

Back in th early '90s (I would have to do a dig to find my log to be more accurate about dates

) I was up at the local lookout one night doing some astronomy with binoculars. I had my head down in the back of the station wagon either checking star charts or writing in my log, when I was lit up by headlights (or so I thought).

It was a bit creepy because I didn't hear any car come up behind me. Sure enough, no car, but I looked up in time to see a bright blue fireball approaching from the East, and the whole town was lit up almost like daylight (just with a blue tinge like light from an arc welder).

The fire ball broke in half, then as it went over head, both halves broke into lots of little bits leaving orange trails, and that's when I heard a sizzling sound.

It's the only meteor/bolide I've ever heard. This story got me an AST tee shirt once!

Al.

mch62 (Mark) · #10 05-08-2009, 07:55 AM

Herd one about 12 months ago ,went right over head fairly slow and sounded like the sound loose plactic sheeting on the back of a truck flapping in the wind makes.No boom

OneOfOne (Trevor) · #11 05-08-2009, 08:22 AM

Apparently many of them make a sort of "woop, woop, woop" sound, sort of like a helicopter and is believed to be created if the meteor is tumbling as it comes in.

About 20 years ago I was driving north along Burke Rd (anyone in Melbourne will know just how "so not dark" the sky there would be) and I saw this bright white streak coming in in the north and heading west. Bits of material dripped away from the main body then it just disappeared. A couple of seconds later I heard a muffled "boof....". It must have been loud to be heard inside the car, with the window up, radio on!

Karls48 (Karl) · #12 05-08-2009, 10:23 AM

Most of meteors lit up at altitude 80 to 100km. That means that any sound they may produce would reach ground observer 3 to 4 minutes (providing that meteor was directly overhead) after the sighting. There are reports of people hearing hissing sounds while watching large meteor. As this cannot be the sound of meteor reacting with atmosphere as there is not time delay, some scientists explain it that meteor during the interaction with atmosphere generate VLF radio waves. Some thin objects on the ground vibrate when receive those VLF signals, producing hissing sound.
Also there seems to be very few meteors that produce sonic boom. Most of meteors burn up at very high altitude where air is very thin and they are surrounded by plasma that seems to inhibit sound transmission.
I have personally never heard meteor sound, but my next project will be to add microphone with parabolic dish to my meteor capture camera.

StevenA (Steven) · #13 05-08-2009, 11:00 AM

I was lucky as my intro just after buying a scope was seeing a fireball. I had just packed up early and went out onto the porch to practise finding Constelations when a bright light decended into veiw and exploded into a shimmering ball of sparks. They were almost liquid like and brighter than anything I had seen before. It was magnificent. I can't wait to see another. (What are the odds of seeing another anyway?) I saw from my suburban home in Dandenong/Springvale area. I suppose I heard nothing emit from the fireball as the noise of traffic and general noise pollution would have smothered the sound, if any. I still do not know anyone one else who may have seen this event in Dec' 2007, but I remember it very well...

Jeeps (Sam) · #14 05-08-2009, 12:40 PM

I live in a darkish sky location that's elevated (a few hundred metres up) and if you stand and look up long enough (about 10-20 minutes) you're guarunteed to see a shooting star. I heard a hissing sound from one a few years ago, it was probably the brightest i've seen. Just last week i arrived home late in the evening got out of the car and looked up and not 5 minutes standing there i saw a faint one, then it burned out after 2 seconds or so and then it was followed by another 3 or 4 in the same spot each about 10 seconds apart, all almost identical. It was breathtaking and i had never seen that before.

cheers

h0ughy (David) · #15 05-08-2009, 12:54 PM

Professor Colin Keay is an expert on the topic and his views on the topic can be found here http://home.pacific.net.au/~ddcsk1/gelphonx.htm. Colin has been retired for some time now, and is no longer at the Uni of Newcastle.

Waxing_Gibbous (Peter) · #16 05-08-2009, 07:28 PM

I have heard one (I think). It was more a "crack" than a boom, but there was a distinct "sszzzt" accompanying it. It was also the first one I'd ever seen, so I was really, really chuffed! It was amazingly bright - like an arc-welder. I think it landed in my neighbour's paddock, but it's very diffficult to judge distances of unfamiliar objects in the day, let alone at night.
The reason I say "I think" I heard it, is that acoustics where we live are pretty weird and you can hear the neighbours arguing 2 kliks away and not hear a chainsaw at the end of the garden.
Also,there are lots of people out 'varminting' with rifles at night. Like Falluja with cows.
I still like to think it was the meteorite (or bollide or whatever) though.

Outbackmanyep · #17 05-08-2009, 10:29 PM

You want to see some AWESOME meteor films??
go here: http://www.meteorites.com.au/films/

And here is a sonic boom recording of the Bovedy meteorite which Eileen Brown inadvertently recorded while taping bird sounds, 25th April 1969. (34 seconds in!)

http://geologi.snm.ku.dk/nyheder_gm/...109/bovedy.wav

Cheers!

Moon (James) · #18 06-08-2009, 11:38 AM

Quote:

You want to see some AWESOME meteor films??
go here: http://www.meteorites.com.au/films/

Great videos! This thread has motivated me to see if I can film one myself.

MrB (Simon) · #19 06-08-2009, 11:41 PM

Yeah some great vids there.
Have seen a couple of them before but plenty of new ones for me.
Cheers OBMY

mental4astro (Alexander) · #20 16-08-2009, 10:28 PM

I believe I heard one about 15, 20 years ago.

I remember old timers talking about how they judged the pitch of a falling projectile/bomb, to gauge the proximity of the likely place of impact. You know, the changing pitch whistle. The higher the pitch & shorter the time of change, the closer the likely proximity. Another thing mentioned is that for the really close one's, the whistle stopped for a split moment just before impact.

One night, way back when, in the wee hours of a Sunday morning, I heard this same whistle pattern, including the cut-out of the whistle. The impact was an almighty smash, like it hitting a tin roof. It really spooked me as I lived in Redfern at the time & my first reaction to the crash was someone was tearing down somebodies house without their permission.

After calming down, I got to thinking about what I had just heard & remembered the above sound pattern. The impact site was not 50 metres away on the edge of Cleveland street. A small hole of about 20 to 25cm diameter & quite deep & no crushing around the edge, very unlike any pot hole. If the projectile survived impact, traffic on the road would not have been too happy to stop it for its retrieval.