Strange streak discussion: 2004 Dec 7 APOD

[Maxx]

the light bulb is burning out and this causes two major artifacts in the image. the first being the apparent "dust" which is a glare below and to the right of the lamp. the streak is the "shadow" caused by the intense light of the bulb giving its all.

[monkeymissile]

for those of you reading the Dark Tower series, this is an easy one.........it's the Path of the Beam

[none]

It has been pointed out at http://slashdot.org that the timestamps on the photos are not in sequence. The actual third shot, the one that immediately followed the streak, was apparently not actually posted. So no way to tell if there are ripples in the water where the small fireball could have splashed. Has anyone mentioned "space junk" yet. We know that there are thousands of pieces of trash in Low Earth Orbit, and every now and then a moderately big piece makes it to the ground, perhaps leaving a short-lived smoke trail. If 30 seconds passed between shots, the smoke may have dissipated.

[Guest]

Here's another, close ALTERNATIVE EXPLANATION

The camera has caught the flash of the light bulb burning out. Zooming on the flash shows the bright half-ring around it is perfectly circular. This suggests it’s an image artefact from internal reflections near (or in) the focal plane. The little bight diagonal streaks on the flash ring reinforce this idea that they are internal reflections.

As for the long, dim straight streak, it could also be an image artefact. Without knowing the details of the digital camera focal plane array, it *could* be an artefact of the image read-out electronics or CCD after the bright overload spot of the bulb flash.

You hit it on the spot. The "trail" is an optical artifact, either by the CCD or the optics cause by the bulb burning out.

[Stephanie]

Saw a very similiar dark "shadow" across the sky here in New Mexico. It lasted about 5 minutes and was a bit broader than the one in this picture. It didn't seem to have anything to do with the sun as it was on the opposite side of the horizon from it. The sky was clear and there were no planes present in the air. It just looked like a big straight shadow stretching down from the sky. Was rather eerie to see.

[undefinedvalue]

Do contrails or the shadows thereof move fast enough to evade the shots 15 seconds before and after the main shot? Also, for those who are proponents of the lightning theory, have you considered St. Elmo's Fire?

[rps]

I think it is the shadow of the flash that originates at the light pole . The flash is from the light bulb expireing.

[bpowah]

This may have been suggested as I have not read all comments.

If the bulb was caught in the act of flashing it's last lumen, and perhaps this is the type of lamp that has a downward-focusing reflector. Then anything reflective below the lamp would cast a shadow of the pole upward and back.

[guest]

Perhaps I'm confused but I compared the alleged before picture to the event picture and they are the exact same picture at the exact same moment. Compare the ripples in the bottom right of each picture to the other and they are the same. The third picture is different. So I conclude this has to be a fake.

[mcstar]

OK, here's the ultimate death to the shadow "cast" from the light theroy... shadows are, by definition an absence of light or blocking of a light source. For the lamp to be "casting" a shadow on the sky, it would have to be blocking the source of the sky's illumination! That means you lamp would have to be blocking the sun, or it would have to be illuminating the rest of the sky! Come on now, there is no way that lamp could be illuminating the entire sky uniformly enough to be casting that "Shadow"! It would have to be consuming 100's of megawatts worth of light to do that outside!

[Guest]

my first impression was the shadow from a contrail. i seem them occassionally here in Vancouver Canada.
keep smilin...........

I also think that it resembels a contrail shadow.

http://www.geocities.com/deep_sky_astronomy

[Bill McDonald]

When I first saw this picture I thought of contrail shadows that I have seen before. When I read the other responses I saw that a number of other contributers came to the same conclusion. If it is a shadow, then the flash is unrelated, possibly a spotlight from a small boat.
Usually contrail shadows like this one occur when an aircraft is travelling in a direction away from the sun. The arguement for a contrail shadow could strengthened or weakend by determining where the sun was in relation to this picture. Also, any aircraft leaving a contrail should be flying IFR and therefore be on record with air traffic control.

[phhhuuuccckkk]

It looks to me as though what has been captured is the shadow of the light post in the sky from the light reflecting off of the water. I think that perhaps that spot of light in the picture is the same the the setting sun hitting the light post at the right angle to reflect in that picture and if you look at the left side of the photo you can see the sunlight reflecting off of the water but it is not on the right side which is why the shadow trails off to the right, the light is being reflected up off of the water and the light post is casting a shadow in the sky because of it. Just my 2 cents.

[Guest]

It looks to me as though what has been captured is the shadow of the light post in the sky from the light reflecting off of the water. I think that perhaps that spot of light in the picture is the same the the setting sun hitting the light post at the right angle to reflect in that picture and if you look at the left side of the photo you can see the sunlight reflecting off of the water but it is not on the right side which is why the shadow trails off to the right, the light is being reflected up off of the water and the light post is casting a shadow in the sky because of it. Just my 2 cents.

crap i mixed it up a bit the light IS on the right not the left my bad.

[sst]

The lightis from a object in the background that is causing glare and distortion... probably something small that is passing by on the water of even drifting..

[ladymurasaki]

the streak appears to be a straight line the whole distance from the lamp to the sky? if so - though they are intriguing - this would rule out theories that would include any kind of projectile action, at least the kind that would be reasonably affected by gravitational pull within the space of this shot...

can someone explain what a contrail is exactly? thanks!

this is fun...

[Guest]

1) This can not be a bug. That is just silly. Get a copy of the full picture and look at how small this "bug" would need to be. It would have to be VERY close to the lens to make the trail that long in 1/20th of a second and would have to be impossibly small to create the thin shadow line and the pinpoint flash on the picture. A gnat going Mach 10 couldn't do this.

2) It can not be a meteor. First of all, anything that large would have either obliterated the light or made quite a splash in the bay. Neither is evident. There is another exposure 15 seconds later that shows no ripples in the bay, and the light was checked and there is no damage. Some have tried to argue that is was as small meteor, the size of a marble or a grain of sand. These objects would either burn up in the atmosphere or would lose all their momentum and simply freefall. Nothing that small would still have that much momentum that close to the ground.

Looks light a light blew out plain and simple. The smoke in the foreground looks like smoke from a boat starting up behind the trees in the water between the shore and the bridge the lamp post is on. Besides how could the white column of smoke be created by something that just impacted the light. Did the lamppost emit a plume of smoke preemptively to try and ward of the supposed meteor?

The streak looks very much like a contrail shadow and would explain why the streak ands at the horizon. There is no evidence of the streak near the light post. The reflection of the sunlight is rather bright there and the streak would be very visible if I was created by an object of some kind, but it is not there. That tells me the streak is in the sky, not heading to the lamp post. That would also explain why there is no perspective on the trail. It is the same thickness throughout.

[saymon]

this is rocket model lunch

[pavel]

Illumination appears to be coming from the top right of the image, and the position of the lens is at an angle to this in the foreground, so in IMHO the lens cannot be in the shadow of a 'contrail'.

Further, it is possible that the apparent impact of the phenomenon against the light is a coincidence of perspective, and the flare is actually an artifact of the refraction of the top-right illumination through the translucent covering of the light. Or perhaps, there really was an interaction, though this is not completely possible to determine from the image.

Oddly, the 'trail' reminds me of a night time sighting of a 'meteor trail' seen from Benleigh, Queensland, a suburb of Briusbane, about 3 1/2 years ago. The angle is, in recollection, about the same, and when the streak intersected the horizon there was a burst of light parallel to and just above the horizon. The light conditions were in the latter part of dusk, nearly but not quite full dark.

[Guest]

You hit it on the spot. The "trail" is an optical artifact, either by the CCD or the optics cause by the bulb burning out.

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I agree that the "smoke" is an image artifact, but it seems more plausible to me that the trail is a shadow from the lamp post.

[NotArtBell]

this is rocket model lunch

Rocket Model Lunch -- is that on the dollar menu???

[Andrew Opala]

Assumptions:

The light bulb is definitely the source of this effect because it is at the end of a very linear streak.

Explanation:

Why does this matter?

'When CCD camera's discharge their photon bins, they push photons bin to bin until they reach the end bin and are read by the meter'. Very often these bins can overflow and effect the reading of other lines even though there is no actual light in those areas. There may be some compensation with this camera that does not show a bright streak but rather a dark one. There may also me some evidence that the aperture when it closed cause some correction to be applied as well. It would be interesting to have an explanation of how the aperature and light capture area work together in this geometry.

There is also another reason why this would be happening on the CCD itself and not in reality in from of the camera. The line is linear on the picture which actually signifies a curved line in reality - since the picture is just an estimate of reality it would probably not show a straight line that would leave the view.

Finally, the speed of the line if it was not instantaneous, whould correlate in some way at that distance to some very improbable values. More to suggest that the effect is local to the capture device not the actual reality of the place being photographed.

-Andrew Opala

[Guest]

The angle of the lens has nothing to do with it. A shadow is a shadow and can be seen from anywhere. The fact that this looks like a previous meteroite sighting is totally coincidental and of no relevance to the conversation.

[B]

To me, this looks like a vapor trail. I have seen these before where they appear to slice through the clouds and leave such an impression.

It only appears to hit something on the ground, but actually, it's in the sky, most likely just in the cloud cover.

[tony]

The dark stripe appears to me to have the shape of the lines we'd expect from a rainbow.