wmartin@brl-tgr.ARPA (06/11/85)
There's a rather good weekly radio program I try to listen to called the "BBC Science Magazine"; I suppose its a teanscription service from the BBC, and it is aired on NPR stations here (locally on WSIE, 88.7MHz, Edwardsville, IL). Anyhow, last week's program had a segment about a curious phenomenon encountered by a Japan Air Lines pilot on a trans-Pacific flight. (I didn't record this broadcast, so I can't cite specific figures, as I'm working from memory.) Anyway, this JAL flight was cruising at some normal jet-type altitude (like 30,000 ft or thereabouts) some distance above a rather dense cloud layer. Suddenly, directly ahead, the pilot saw the clouds begin to rise up in an enormous bulge. The cloud bulge grew at fantastic speed, and soon reached up and sideways for distances measureable in miles. The pilot took evasive action, but could not avoid flying through the cloud; he was convinced that he was flying through the results of an atomic explosion, so he had the crew go on emergency oxygen, and he landed at the next available site to have the plane checked and decontaminated if necessary. Well, there was no evidence of radioactivity, and no ground-based phenomenon reported that would explain this occurrence. Normal atmospheric changes, like the formation of cumulus clouds, cannot occur at the rate observed. The JAL flight eventually continued on to its destination. What caused this? Well, the theory is that that airplane had the first observed encounter with a meteor. A several-ton meteor, of several meters diameter, perhaps composed of mostly ice with some stony fragments, could have hit that cloud layer on its way down through the atmosphere. At meteoric speeds, hitting a dense cloud layer is almost equivalent to hitting the ground. The meteor would have fragmented and probably vaporized, transfering all its enormous kinetic and thermal energy to the cloud structure in the form of heat. This would have caused the observed huge boiling-up of the clouds and the formation of such an atmospheric structure. Well, fascinating if true. Here's something else to look up for! Regards, Will Martin USENET: seismo!brl-bmd!wmartin or ARPA/MILNET: wmartin@almsa-1.ARPA
lip@gcc-bill.ARPA (06/12/85)
In article <11270@brl-tgr.ARPA> wmartin@brl-tgr.ARPA (Will Martin ) writes: >What caused this? Well, the theory is that that airplane had the first >observed encounter with a meteor. A several-ton meteor, of several meters >diameter, perhaps composed of mostly ice with some stony fragments, could >have hit that cloud layer on its way down through the atmosphere. Shouldn't that be *meteorite*? Seth Lipkin General Computer Company harvard!gcc-bill!lip "Is art the mirror of life, or what?" - Woody Allen
fritz@utastro.UUCP (Fritz Benedict) (06/13/85)
> In article <11270@brl-tgr.ARPA> wmartin@brl-tgr.ARPA (Will Martin ) writes: > >What caused this? Well, the theory is that that airplane had the first > >observed encounter with a meteor. A several-ton meteor, of several meters > >diameter, perhaps composed of mostly ice with some stony fragments, could > >have hit that cloud layer on its way down through the atmosphere. > > Shouldn't that be *meteorite*? > > Seth Lipkin > General Computer Company > > harvard!gcc-bill!lip It's a *meteor* until it hits the ground. Then it's a *meteorite*. Hitting a cloud is a rather grey area between ( 8-) ). -- Fritz Benedict (512)471-4461x448 uucp: {...noao,decvax,ut-sally}!utastro!fritz arpa: fritz@ut-ngp snail: Astronomy, U of Texas, Austin, TX 78712
brent@phoenix.UUCP (Brent P. Callaghan) (06/14/85)
> Anyway, this JAL flight was cruising at some normal jet-type altitude > (like 30,000 ft or thereabouts) some distance above a rather dense cloud > layer. Suddenly, directly ahead, the pilot saw the clouds begin to rise up > in an enormous bulge. The cloud bulge grew at fantastic speed, and > soon reached up and sideways for distances measureable in miles. The pilot > took evasive action, but could not avoid flying through the cloud; he > was convinced that he was flying through the results of an atomic > explosion, so he had the crew go on emergency oxygen, and he landed > at the next available site to have the plane checked and decontaminated > if necessary. > > Well, there was no evidence of radioactivity, and no ground-based > phenomenon reported that would explain this occurrence. Normal atmospheric > changes, like the formation of cumulus clouds, cannot occur at the rate > observed. The JAL flight eventually continued on to its destination. > > What caused this? Well, the theory is that that airplane had the first > observed encounter with a meteor. A several-ton meteor, of several meters > diameter, perhaps composed of mostly ice with some stony fragments, could > have hit that cloud layer on its way down through the atmosphere. At > meteoric speeds, hitting a dense cloud layer is almost equivalent to > hitting the ground. The meteor would have fragmented and probably > vaporized, transfering all its enormous kinetic and thermal energy > to the cloud structure in the form of heat. This would have caused the > observed huge boiling-up of the clouds and the formation of such an > atmospheric structure. I can't imagine how hitting a cloud layer - no matter how dense - would be like hitting the ground (even at meteoric speeds). Supersonic aircraft, space-shuttles etc fly regularly through dense clouds without a bump. As a skydiver I've fallen through dense clouds without feeling a thing (although I've often wished they really were like soft fluffy cotton wool :-) ) Perhaps the boiling-up was due just to a ginormous thermal from the atmospheric heating in its wake. (Bet those pilots were glad it WASN'T a nuclear explosion !) -- Made in New Zealand --> Brent Callaghan AT&T Information Systems, Lincroft, NJ {ihnp4|mtuxo|pegasus}!phoenix!brent (201) 576-3475
jgpo@iham1.UUCP (John, KA9MNK) (06/14/85)
> In article <11270@brl-tgr.ARPA> wmartin@brl-tgr.ARPA (Will Martin ) writes: > >What caused this? Well, the theory is that that airplane had the first > >observed encounter with a meteor. A several-ton meteor, of several meters > >diameter, perhaps composed of mostly ice with some stony fragments, could > >have hit that cloud layer on its way down through the atmosphere. > > Shouldn't that be *meteorite*? > > Seth Lipkin > General Computer Company > harvard!gcc-bill!lip > > "Is art the mirror of life, or what?" > - Woody Allen Only if it hit the surface of the earth without being completely vaporized, according to Webster. John Opalko AT&T Bell Labs ihnp4!iham1!jgpo
jhc@mtung.UUCP (Jonathan Clark) (06/14/85)
<> I remember reading somewhere that at orbital speeds a meteor would go through the atmosphere in about 2 seconds. That doesn't give it a lot of time to heat up. Also I don't think even a heavy rainstorm is quite as dense as the ground. No, personally I think it must have been a quantum black hole (finally) going off :-) -- Jonathan Clark [NAC]!mtung!jhc
canopus@amdahl.UUCP (Alpha Carinae) (06/17/85)
> > Anyway, this JAL flight was cruising at some normal jet-type altitude > > (like 30,000 ft or thereabouts) some distance above a rather dense cloud > > layer. Suddenly, directly ahead, the pilot saw the clouds begin to rise up > > in an enormous bulge. The cloud bulge grew at fantastic speed, and > > soon reached up and sideways for distances measureable in miles. > > [...] > > > > What caused this? Well, the theory is that that airplane had the first > > observed encounter with a meteor. [...] > I can't imagine how hitting a cloud layer - no matter how > dense - would be like hitting the ground (even at meteoric speeds). > Supersonic aircraft, space-shuttles etc fly regularly through > dense clouds without a bump. 1. Keep in mind that supersonic aircraft, space shuttles and the like are built and designed to slice through air at supersonic speeds. Also keep in mind that even the shuttle, which impacts the atmosphere during reentry at something approaching 5 miles a second would surely burn up without its special heat shield tiles. 2. Meteors generally impact our atmosphere at speeds exceeding 30 miles a second, and are hardly aerodynamically stable! Most are sand grain to pea sized pieces of stone, and vaporize within a second or two, usually at distances above 60 miles from the ground. Occasionally, a bigger (softball sized or larger) meteor impacts the atmosphere, and explodes in a brilliant flash. These are often called "bolides". I do not know if the observed cloud was due to a meteor explosion; if it were I would suspect that the pilot should also have seen the explosion which preceded it. > As a skydiver I've fallen through > dense clouds without feeling a thing (although I've often wished > they really were like soft fluffy cotton wool :-) ) Sure. You're only falling at around 120 mph or so. I guarantee that if you accelerated to 15,000 mph you'd feel it. > Made in New Zealand --> Brent Callaghan -- Frank Dibbell (408-746-6493) ...!{ihnp4,cbosgd,sun}!amdahl!canopus Amdahl Corporation, Sunnyvale CA [This is the obligatory disclaimer..] - - - - - - - - - - - - - - - - - - - - - - - "I call it 'tranya'. I hope you relish it as much as I."
fred@mnetor.UUCP (Fred Williams) (06/17/85)
In article <263@gcc-bill.ARPA> lip@gcc-bill.UUCP (Seth Lipkin) writes: >In article <11270@brl-tgr.ARPA> wmartin@brl-tgr.ARPA (Will Martin ) writes: >>What caused this? Well, the theory is that that airplane had the first >>observed encounter with a meteor. A several-ton meteor, of several meters >>diameter, perhaps composed of mostly ice with some stony fragments, could >>have hit that cloud layer on its way down through the atmosphere. > >Shouldn't that be *meteorite*? > It is a meteor until it hits the ground. However I doubt that it was. From what I remember of the original posting the observer saw clouds building at a very high rate. The vertical wind rate in some thunderstorm clouds can be very high. Condensation of water vapour liberates heat to expand the air in the cloud and the process feeds on itself. Updrafts in excess of 200 mph have been inferred from the size of hail stones. (ie. that is the speed required to support the stone during formation). I expect watching the cloud form would be quite a sight. I wish I could see one myself someday. (from a safe distance, of coarse). This does not represent that only explanation, but probably one more likely than a meteor. I suppose it depends on how fast the cloud built and how accurate the measurements were. Cheers, Fred Williams > Seth Lipkin > General Computer Company > harvard!gcc-bill!lip > >"Is art the mirror of life, or what?" > - Woody Allen
julian@osu-eddie.UUCP (Julian Gomez) (06/18/85)
> > Anyway, this JAL flight was cruising at some normal jet-type altitude > > (like 30,000 ft or thereabouts) some distance above a rather dense cloud > > ... > > I can't imagine how hitting a cloud layer - no matter how > dense - would be like hitting the ground (even at meteoric speeds). > Supersonic aircraft, space-shuttles etc fly regularly through > dense clouds without a bump. As a skydiver I've fallen through > dense clouds without feeling a thing (although I've often wished > they really were like soft fluffy cotton wool :-) ) > ... Meteor speeds are drastically higher than skydiving or shuttle speeds, so any mass in front of a meteor could have dramatic consequences. Maybe it was The Giant Ninja Mushroom Meets Godzilla. !-) -- Julian "a tribble took it" Gomez The Ohio State University {ucbvax,decvax}!cbosg!osu-eddie!julian
bob@islenet.UUCP (Bob Cunningham) (06/19/85)
The time was 2306, the date 9 April 1984, the flight was JAL 36 (a 747
piloted by Capt. Charles L. McDade, with 41 years of flying experience).
They were 45 minutes east out of Tokyo on the way to Anchorage, Alaska.
He saw a large (perhaps 200 miles in diameter) mushroom cloud rising
from 14,000 feet to 60,000 feet in about two minutes (a rate of climb
of 260 miles per hour).
Three other commercial aircraft flew near the cloud, and right
after McDade reported what he said looked like the effect of a nuclear
explosion, an F-4 Phantom from the Japanese Air Self-Defense Force was
dispatched to the scene and collected a dust sample.
All of the aircraft were checked after landing; no radiation above
normal ambient levels was found. The aircraft crews were interviewed; no
one saw a flash or fireball.
Seismological records from various sources have been examined; no signature
typical of a nuclear detonation in the ocean has been found. A large
increase of volcanic activity in the western Pacific was recorded on 8 and
9 April. Pilots from the Japanese Maritime Safety Agency had reported an
eruption of an underwater volcano (Kaitoku Seamount) two weeks previously,
located 80 miles north of Iwo Jima and 900 miles southwest of the reported
location of the mushroom cloud. However, winds were blowing southeast
during 8 and 9 April.
Since the event, Dan Walker of the Hawaii Institute of Geophysics has been
doing his best to spread the word about this phenomenon and dig up further
information.
The latest word from Dan is:
Since publication of our report ("Kaitoku Seamount and the Mystery
Cloud of 9 April 1984") in _Science_, syndicated articles
referencing our work have appeared in newspapers across the country
on three different weekends. I have been on two radio programs
(NPR and the Canadian Broadcasting Corporation), a CBS radio spot,
in _Science_News_, _Newsweek_, the _New_York_Times_, _Science_85_,
and an upcoming issue of _Omni_. The major benefit of all this in
scientific terms might be some reasonable suggestions as to a
possible cause, or, if man-made, an outright confession (or "leak")
by one of the parties involved. To date, I know of only one
physically reasonable hypothesis in the works and will pass it on
when it beomes finalized.
--
Bob Cunningham {dual|vortex|ihnp4}!islenet!bob
Honolulu, Hawaiibuck@shell.UUCP (Lester Buck) (06/19/85)
> I can't imagine how hitting a cloud layer - no matter how > dense - would be like hitting the ground (even at meteoric speeds). I remember from ground school that air filled with water vapor is less dense than dry air, even though is feels "heavy". If clouds are water vapor, doesn't this make them *less* dense than the surrounding air? Unless there was a storm in progess with condensed water, I guess. A. Lester Buck {ihnp4, pur-ee, ut-sally}!shell!buck
msb@lsuc.UUCP (Mark Brader) (06/20/85)
> > Anyway, this JAL flight was cruising at some normal jet-type altitude > > ... Suddenly, directly ahead, the pilot saw the clouds begin to rise up > > in an enormous bulge. The cloud bulge grew at fantastic speed, and > > soon reached up and sideways for distances measureable in miles. > > > > ... the theory is that that airplane had the first > > observed encounter with a meteor. > I can't imagine how hitting a cloud layer - no matter how > dense - would be like hitting the ground (even at meteoric speeds). I was just reading an article about the great mysterious explosion in Tunguska, Siberia, in 1908, and it occurred to me that this might have been a similar event. What was observed in 1908 was something streaking across the sky, followed by a vertically oriented flash of light and sounds of a tremendous explosion. The area was wilderness even before the devastation and what with the war and the revolution nobody got around to exploring the place for about 15 years. They found the trees blown outward from the center over a radius of quite a number of miles; but at the very center, the bare trunks of trees were still standing. This proves that what hit the ground was not a solid object but a blast of air (very hot air; everything was scorched). So perhaps what the JAL pilot observed was a smaller version of this incident. It wasn't big enough to be heard noticeably at great distances, and if it made a flash it was lost in the clouds; but there was a large expansion of air, and that suggests it was driven by heat. Perhaps this event simply was not powerful enough for the blast of hot air to reach the ground. The trouble is that we don't know what happened in 1908. According to the article I read, which was in the latest issue of "Science 85", the leading theory nowadays is that the remains of a small, dead comet hit the earth. (One does have to explain why no comet was seen--hence the "small, dead"). Another tenable theory is that it was a chunk of antimatter. (One then has to explain what chunks of antimatter are doing in our neighborhood.) The proposal that it was a tiny black hole is disproved, by the way; the trees would not have remained standing in such a gravity. Does anyone know how close to the scene the nearest land- or sea-based observers would have been, this time? Mark Brader
paulh@tektronix.UUCP (Paul Hoefling) (06/20/85)
<>> What caused this? Well, the theory is that that airplane had the first
<>> observed encounter with a meteor. A several-ton meteor, of several meters
<>> ...
<>
<> Shouldn't that be *meteorite*?
<>
< It is a meteor until it hits the ground.
Actually, when something is flying through space it's a *meteoroid*, it
becomes a *meteor* when it enters the atmosphere and begins to burn, and
if it manages to survive and strike the ground, what's left of it is a
*meteorite*.
Yours for pickier terminology...
Paul Hoefling
Information Pack Rat
uucp: {allegra,decvax,ihnp4,ucbvax,zehntel}!tektronix!paulh
--
Paul Hoefling
Information Pack Rat
uucp: {allegra,decvax,ihnp4,ucbvax,zehntel}!tektronix!paulhjgpo@iham1.UUCP (John, KA9MNK) (06/24/85)
> > I can't imagine how hitting a cloud layer - no matter how > > dense - would be like hitting the ground (even at meteoric speeds). > > I remember from ground school that air filled with water vapor is > less dense than dry air, even though is feels "heavy". If clouds > are water vapor, doesn't this make them *less* dense than the > surrounding air? Unless there was a storm in progess with > condensed water, I guess. > > A. Lester Buck > {ihnp4, pur-ee, ut-sally}!shell!buck Clouds aren't made of water vapor. They are made of minuscule water droplets. Don't forget that water vapor is invisible. You begin to see clouds when vapor-laden air rises to a point where it's cool enough for the vapor to condense. You're right that moisture-laden air is less dense than dry air. The picture changes when the water vapor condenses. Then you've got a bunch of droplets hanging around, and that's a heck of a lot of mass for a meteor to try to push out of the way. Don't forget that water (and air, if you're going fast enough) is incompressible. John Opalko AT&T Bell Labs Naperville, IL ihnp4!iham1!jgpo
kene@tekecs.UUCP (Ken Ewing) (06/24/85)
> I remember from ground school that air filled with water vapor is > less dense than dry air, even though is feels "heavy". If clouds > are water vapor, doesn't this make them *less* dense than the > surrounding air? Unless there was a storm in progess with > condensed water, I guess. > > A. Lester Buck > {ihnp4, pur-ee, ut-sally}!shell!buck I remember from ground school that higher humidity results in "thinner" air (the rule was *The Three H's*: High, Hot, and Humid). However, I also remember from physics class that clouds are *not* water vapor. They are microscopic droplets of water (still in liquid state) that coalesce around microscopic dust particles. These droplets and dust particles are so small that they float in the air until enough of them merge and become heavy enough to precipitate out of the atmosphere as rain. Ken Ewing [decvax, ucbvax]!tektronix!tekecs!kene
GMS@psuvm.BITNET (06/24/85)
I remember reading that the 'small, dead' comet that supposedly created the
1908 explosion, was hypothesized to be a fragment from Encke's Comet. This
comet is a small one with a period of about 3.5 years and with an orbit that
crosses that of the Earth. Having observed it a number of years ago (late
1970's) I can testify that it is very difficult to see (although I only used
an 8-inch scope).
Most comets are of this category, not even becomming of naked-eye visibility.
Consider IRAS-Araki-Alcock (in 1983) which came very close to the Earth, and
was not a very spectacular sight. (At least to non-astronomer types) Since
this one was estimated at about 1 mile diameter and about 6 million miles away
it would not have taken much deviation in its orbit to have a spectacular effec
t on the Earth.
Gerry Santoro
Penn State University
. . . !psuvax1!santoro (uucp)
. . . !psuvax1!psuvm.bitnet!gms (uucp-bitnet gateway)
wfl@maxvax.UUCP (w linke) (06/26/85)
[] >> > I can't imagine how hitting a cloud layer - no matter how >> > dense - would be like hitting the ground (even at meteoric speeds). >> >> I remember from ground school that air filled with water vapor is >> less dense than dry air, even though is feels "heavy". If clouds >> are water vapor, doesn't this make them *less* dense than the >> surrounding air? Unless there was a storm in progess with >> condensed water, I guess. >> >> A. Lester Buck >> {ihnp4, pur-ee, ut-sally}!shell!buck > >Clouds aren't made of water vapor. They are made of minuscule water droplets. >Don't forget that water vapor is invisible. You begin to see clouds when >vapor-laden air rises to a point where it's cool enough for the vapor to >condense. > >You're right that moisture-laden air is less dense than dry air. The picture >changes when the water vapor condenses. Then you've got a bunch of droplets >hanging around, and that's a heck of a lot of mass for a meteor to try to >push out of the way. Don't forget that water (and air, if you're going fast >enough) is incompressible. > > John Opalko > AT&T Bell Labs > Naperville, IL > ihnp4!iham1!jgpo If you identify a parcel of air in the atmosphere, and follow it as it enters a region of temperature/pressure such that its water vapor condenses, it will become a cloud; yet the mass of the parcel has not changed! Which is another way of saying that clouds are not something *added* to the atmosphere, and the mass of air to be moved is not different if the water is distributed as microscopic drops instead of as gas. But before this discussion gets too far out of sight, may I ask if anyone on the net can cite any references for the original posting? If I remember correctly, it was just hearsay about some Japanese airliner that had to avoid a rapidly-forming cloud. Sounds like the National Enquirer to me. W. F. Linke
mjs@eagle.UUCP (M.J.Shannon) (06/26/85)
> > If you identify a parcel of air in the atmosphere, and follow it as it > enters a region of temperature/pressure such that its water vapor condenses, > it will become a cloud; yet the mass of the parcel has not changed! > Which is another way of saying that clouds are not something *added* to > the atmosphere, and the mass of air to be moved is not different if the > water is distributed as microscopic drops instead of as gas. > > W. F. Linke Yes, but the volume of that packet becomes somewhat smaller as the vapor condenses to droplets. If you consider that the volume of atmosphere an extraterrestrial object must pass through is constant, then the amount of mass it must displace is thus much greater. -- Marty Shannon UUCP: ihnp4!eagle!mjs Phone: +1 201 522 6063
daleske@cbdkc1.UUCP ( John Daleske ) (07/02/85)
Yes, in response to the question of the validity of the source for the JAL report, I heard it on All Things Considered on National Public Radio. They reported on it for two days, originally with some inuendo about some testing by the Soviets and relating it to the area where the Soviet-downed JAL airliner went down.