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Re: (meteorobs) TX/NM Fireball
Jim Bedient wrote:
>Thought you might enjoy this account I got via the AMS electronic fireball
>form of the TX/NM event. Some things in this account I haven't seen
>elsewhere, the sound effect (I asked, and the observer was adamant that it
>was only 5-6 seconds after seeing the fireball). Also the duration of the
>smoke trail is given as two hours, quite lengthy! I like the "stealth"
>F-14's though!
Rather than repeat the whole post...
I find it interesting that this event appears to have occurred near or
overhead White Sands. Perhaps there are others on this reflector who have
been there during tests. Unfortunately, I've only been out there once when a
sky test of the sort I describe below occurred; but reading the eyewitness
report certainly reminded me of that day.
I can't say what the vehicle was nor what the actual test was (because I
didn't need to know, so I wasn't told); but once upon a time, I was out
there with a special sensor system to measure the results of a test. The
test was some kind of "shootdown" whereby some kind of vehicle re-entered
the atmosphere somewhere over central New Mexico, and some kind of
projectile was fired from somewhere, whether on the ground or from an
aircraft I don't know, to intercept and destroy the vehicle.
There were hundreds of other sensor platforms all over the southwestern US
mobilized for the event with thousands of personnel involved. The sensors
included cameras (the "observatories" which the eyewitness mentioned),
radars, and who knows what else. White Sands has a special closed-circuit
communications net over which launch and other data is exchanged, with each
observation site tied into the network. All listeners were informed of the
complete status of the vehicle re-entry so we knew when to look for it.
When the vehicle began its re-entry, some seconds passed before it could be
observed streaking through the sky. Perhaps streaking is the wrong
description to use as all you could see was a little tiny shiny speck
crossing the sky. As far as I remember, there was not even a contrail. We
knew exactly where to look so the object was not difficult to spot once it
came low enough.
Then the projectile was fired from wherever; this could be seen as an
extremely fast-moving tiny speck of white approaching the re-entering
vehicle. I was not looking at the vehicle at the moment when the intercepter
struck the vehicle, but did see the flash out of the corner of my eye. The
interception resulted in a rapidly-expanding and stationary fireball (a ball
of fire, not a streak of "fire" such as our meteor fireballs") which
quickly, within less than a second, became an expanding, dark and
dirty-looking cloud of what must have been debris. I can't remember whether
the cloud continued to drop on the same trajectory of the original vehicle;
but if it did, it must not have been very far, just noticeable to the naked eye.
Here are two major differences between a meteoric fireball and a re-entering
space vehicle being intercepted: the vehicle leaves no marked trail other
than, perhaps, a slight contrail or possibly, but not likely, an exhaust
plume; and the debris cloud resulting from the interception does not
continue to move on the same trajectory as an exploded bolide does.
But the resulting audio effects have got to be heard to be believed! Sonic
boom? Uh-uh...this really sounded like a real explosion and shook the van
box within which our equipment was mounted. I don't really remember for sure
now; but it seems to me that the boom did not occur for at least 10 seconds
after the interception. It was a very deep and penetrating boom preceded by
a barely audible sharp crack. We later heard that many observation sites
reported not hearing any boom. Apparently, the winds at the interception
height were sufficiently strong as to dissipate the sound downwind but not
upwind. We were downwind but southeast of the interception with, as it
became clear as the debris cloud drifted through the sky, a westerly wind;
so we were actually not even in the direct path of the winds within which
the interception occurred.
We heard many echos of the boom, the last audible occurring some 5 or 6
seconds after the first boom and probably ground reflections off the
mountains to our east above Alamogordo. The description of the bolide sonic
boom sounds very similar to that which we heard from the vehicle destruction.
The resulting debris cloud was more circular in shape rather than a trail,
with some "arms" of smoking debris shooting out in all directions, most
clearly dropping toward the ground; all of those smoke "arms" disappeared
within a few tens of seconds later. Without knowing exactly where the
interception occurred relative to our own location (the ground distance, for
example), I'm reluctant to guess how far the cloud was actually blown during
the time it was visible. From our site, it began high in the northwestern
sky and finally disappeared when upper atmosphere winds blew it over the
mountains to our east, perhaps an hour later. I theorize that the
interception and resulting destruction of the vehicle must have released
incredible amounts of heat and other energy, the heat energy alone creating
a huge vapor cloud just like a normal rain cloud. I suppose this would also
occur when a bolide explodes. The duration of such a cloud, it seems to me,
would depend entirely on local atmospheric conditions at the altitude and
time of explosion. Thus, I would expect that a given bolide, exploding at
different places over the earth where the atmospheric moisture content might
be different, would probably produce a vapor cloud which time of visibility
would be highly dependent upon the winds aloft in addition to the humidity
at that altitude. The description of the bolide's cloud sounds very much
like what we observed from the vehicle observation.
The other observations of the eyewitness concerning personnel activity
around the White Sands area are very consistent with a test of the sort
which we observed. The test occurred during the day, during the early
morning to the best of my recollection. They do this because photographic
observation of the interception is crucial to evaluate the tests. If the
event which the eyewitness observed was actually a test, and had the
eyewitness been traveling on the highway between Las Cruces and Alamogordo,
he/she would have noticed signs warning that the road would be closed for
several hours while the test was conducted. From the report, it appears that
the witness was between Las Cruces and Socorro, some 50+ miles from White
Sands, and so did not have the opportunity to see whether the road crossing
the range was actually closed, which would have been an almost certain
giveaway that the event was actually a test rather than a bolide.
To conclude, the several events which make me believe that the event was
really a bolide and not just a test include the initial observations of the
"green" meteor trail plus no indication that the object violently exploded
at the end of the trail as it was "intercepted" or destroyed by ground
command. But what happened after that, i.e., the several remaining pieces
flying off in all directions, could apply equally to either a destroyed
vehicle or a bolide.
I submit that the location of this event, plus many other observable aspects
of the event, raise the question in my mind whether the event might not have
been some kind of test conducted over White Sands rather than an actual
bolide. The eyewitness's description of where the event occurred in the sky
seems to place it somewhere to the east of Socorro and Las Cruces which
would be over White Sands. I think that anything that anybody sees in the
skies over White Sands should be considered to most likely be some kind of
test unless proven otherwise.
One thing that really makes me wonder about the accuracy of the eyewitness's
report is the description of the sonic boom, and that the eyewitness insists
that it occurred after only 5 or 6 seconds after the event. The winds over
southern Mew Mexico are predominantly westerly. The eyewitness was
apparently to the east of the event; thus the sonic boom which the
eyewitness heard not only traveled against the likely-prevailing winds, but
it also should have been delayed by the same winds (you can hear this
delaying effect on thunder resulting from lightning strikes; those who are
downwind will hear the thunder much sooner than those who are upwind, who
may not even hear any thunder). The 5 or 6 seconds before the boom occurred
for the eyewitness would probably have been 3 or 4 seconds with no wind,
which would place the event less than 5 kM from the eyewitness. This seems
rather close to the ground for a bolide. Anybody else have any comment?
SteveH
Shrewsbury MA
P.S. By the way, Jim, I believe that the eyewitness's account of the
"stealth F14s" is actually referring either to the real stealth F117As plus
F14s, or just to the F117As with the eyewitness not knowing that the F14 is
a totally different aircraft (the F14 is the Tomcat of "Top Gun" fame and
only flown by the Navy; the F15 is flown by the Air Force and I believe
there was a squadron or two at Holloman when I was there; but they are
normally based at Luke AFB in Arizona; I don't know about the F16). If the
eyewitness actually saw F14s, they probably would have come from Nellis AFB
and then only if there was a test in which the Navy had a deep interest. In
other words, I believe that the eyewitness misidentified the aircraft seen,
which most likely were *only* F117As, and were undoubtedly not actually
participating in either any test event nor were conducting any search
exercises for remains of the bolide. It would also be highly unusual for
F117As to be seen from the ground anywhere but in the immediate Holloman AFB
vicinity.
F117As are based and flown out of Holloman Air Force Base near Alamogordo
and are quite common over the Alamogordo skies; they are very easily
recognizable but are extremely difficult to see from the front or rear
aspect unless they fly overhead or you catch them during the few brief
moments as they bank. In fact, they are nearly *impossible* to see when
flying directly toward or away from you.
White Sands Missile Range and Holloman AFB do not use F117As to conduct
ground searches (such as for debris from tests or bolides); they have other
aircraft specially outfitted for that demanding role, including helicopters,
particularly from the Army base down near El Paso.