Strange streak discussion: 2004 Dec 7 APOD

[RJN]

What is the strange streak and flash on the 2004 Dec 7 APOD found here: http://antwrp.gsfc.nasa.gov/apod/ap041207.html ?

In an email from the photographer who took the picture, Wayne Pryde, Wayne said:

I had taken 38 shots at 15 second intervals at a shutter speed of 1/20 and aperture of 5.6. I can confirm that there were definitely no fireworks happing on that evening.

As stated in the APOD, I am not sure what caused the streak and flash. My hope is that this discussion will zoom in on the correct answer or narrow the realistic possibilities.

- RJN

[paulgitto]

I have seen lightning similar to this, where only the top of a utility pole has a bright flash, without any bolt coming down from the clouds.
If you look at the current weather conditions in that photo, we see that the sky is ripe for lightning. I believe you caught an ionization trail, that caused the lightning, which may not have been bright enough to cause a bolt to be seen. This trail would not be visible to the human eye, as the flash would have directed the viewers attention to itself, as well as the brightness would have caused too much glare for the eye to see it.
The odds of lightning hitting a pole are much higher than a meteor doing the same. If a meteor did strike the pole hard enough to cause such a flash,there should be some damage.
This still is a very rare photo, which explains why a pole would seen to explode without a visible bolt hitting it.

[wef]

There is no hit on the utility pole. That is something else. This strikes in the distance.

[pauld@exploratorium.edu]

I've seen a similar phenomenon many times before.
Perhaps it is the shadow of a contrail on the air?

The shadow of a contrail falls on hazy air.
Often contrails are straight lines.
When you are inside the shadow looking along it you can see the shadow. Look at right angles and you cannot see the shadow.
When the contrail drifts due to wind, you are no longer inside the shadow and cannot see it.
This is why it is visible only briefly.

Paul Doherty
Senior Staff Scientist
The Exploratorium

[Bruck]

The dark streak looks like a shadow caused by the lightpost. The source of light may be a lightening strike that coincidentally flashed more or less directly behind the lightpost in the distance. I have witnessed such elongated sky shadows during lightening storms at night where small dense clouds block the light.

[fireking]

I've seen shadow lines very similar to the one in the picture. I've seen where a jet, as it zooms high over head, casts a shadow that travels at jet speed. The shadow is visible through the air if the sun is at a shallow angle and there is bright, possibly dusty or hazy sky between the observer and the dark, cloudy background. The speed of a jet would explain the rapid appearance and disappearance of the line. Quite lucky to catch it!

[chromian]

It seems that there is a whitish vapour around the pole. Is this smoke?

[geon]

It could very well be a hair/dust on the lens.
Or, at a shutter speed of 1/20s, it could be an insect flying by.

[onyx]

if you want to be crazy and creative, one could argue that it could be a wrinkle in the time-space continuum. i don't know enough to provide valid reasoning, but it is possible. slight distortions in space could cause a weird, inexplicable shadow.

[Kellam Mackenzie]

But I'll ask anyway. It looks to me like the streak is a trail which begins, not ends, at the light pole.

You say the lamp inside the light pole fixture isn't working. Was the lamp globe burst, or whole and just not working? If the lamp was burst, I'm wondering, if it burst precisely at the moment of exposure, maybe the whitish cloudy looking stuff is the gas exploding out of the lamp and the streak is the trail of some lamp debris shooting from it. I realize that it would have to be some kind of powerful explosion to make a streak that long, but there is a lot of pressure in streetlight lamps, so maybe it's possible.

Please forgive me if this is indeed silly; I'm not a scientist, not by a long shot!

[schulk88@hotmail.com]

My guess is that somebody was testing a relatively weak directed-energy weapon/beam and used the light post for target practice. The "shadow" marks the path of the beam, and witnesses might have seen an aircraft at the other end -- or the beam may have come from a high-flyer, or a satellite.

schulk88@hotmail.com

[Guest]

Is this a digital or film photo?

[BRENT]

I have seen what is described as "ball" lightning twice in my lifetime. Once a single light bulb just over my head exploded. The other time it hit a castiron stove with someone leaning against it and tossed him the length of the room.

[Guest]

I've seen shadow lines very similar to the one in the picture.

This gives me an idea.

The light, when inspected, was not working. This time of the evening (just after 6PM) is when automatic lights often come on - we can apparently see other lights on in the picture.

When lights burn out at startup, they often flash, briefly and brightly. I can't make out the design of the light, but, is it possible that the photographer captured a light bulb burning out -- and the line is the shadow of the light housing? Depending on the design of the housing, a burnout flash could illuminate everything around it, except for the column of air/mist shadowed by the housing.

smith @ canada.com

[ogre]

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

[just a casual observer]

Has anyone else noticed that the flash has a bowed arc at about a 90 degree angle to the dark streak? this is just a what-if, but if it were a meteor could the shot have caught the object as it was just passing close to the light pole, but not actually hitting it? At the speed it would have been traveling there would have been a pretty good shock wave thrown out right? - what are the chances that it could have taken out the bulb without doing any damage to the pole itself?

[Ace Lightning]

It certainly looks like some kind of "incoming" to me. I can see what appears to be a shockwave around the bright spot at the lower end of the streak; the light pole seems to be between the shockwave and the camera. (It would be helpful to know whether anyone heard an unusual sound around the time that picture was taken.) The light pole just happened to be visually near the impact point, and doesn't really have anything to do with what happened. I also think that the streak is far too straight to be an ionization trail (and probably too straight to be the shadow of a contrail either). My guess is something like a very small meteorite or piece of space debris - something moving at a high enough velocity to create a small shockwave, with the attendant flash of light.

[Guest]

I used the gimp program to cut two images from before and during the event, and used the cross-eye technique to overlap the images carefully.

The flash appears to be offset slight to the right from the top of the light pole, and seems to be in the bay behind it, a good distance out, say 1/2 mile or so.

[PappyShappy]

I like to look for the simplest explanations, I think it's the end of the flight of a small signal flare.

[love love]

it has to be a ufo. or a gas line

[maestro30]

I like this one the best




This gives me an idea.

The light, when inspected, was not working. This time of the evening (just after 6PM) is when automatic lights often come on - we can apparently see other lights on in the picture.

When lights burn out at startup, they often flash, briefly and brightly. I can't make out the design of the light, but, is it possible that the photographer captured a light bulb burning out -- and the line is the shadow of the light housing? Depending on the design of the housing, a burnout flash could illuminate everything around it, except for the column of air/mist shadowed by the housing.

smith @ canada.com[/quote]

[just a casual observer]

The only problem I see with the burnout-shadow theory is that the shadow passes up and away from the light pole - The flash would have to have been at the bottom of the pole for it to throw that type of shadow 'up' into the air...

[Gail Clowers]

It appears to me that the shadow originates from the bright light at the pole. It would take quite a light and just the right atmospheric condition.
Great picture.

[frausty]

I think the light was caught in the act of burning out/exploding and the dark streak is a shadow on the lens or possibly the in the air like smith@canada stated.
If the camera was on autoexposure, the flash of light could make the rest of the photo darker than the exposure before or after. Maybe it is just a dirty lens.

[Steve]

Is there any chance of getting a high-res close up of the pole? This might settle whether or not it hit the pole or behind.

THe notion that is the shadow of the pole doesn't make sense. Since the flash is either at the pole, or if not, _directly_ behind it, the shadow would be pointing straight at the camera, not up to the left.

It looks like a contrail, but has anyone ever seen one come below the horizon? Even as a shadow? Doesn't make sense. Besides, a contrail has to be pretty wide, this streak is obviously not very wide and it is also very "neat".

Any other witnesses? Can the photographer confirm for sure whether or not whatever it was actually hit the pole? Did he go over there and have a look?

Was there a sound?

If the camera was automated and you weren't there to hear it, did it make a sound anyway?