Strange streak discussion: 2004 Dec 7 APOD

[Guest]

I've created a survey. The software allows only 10 entries. I put them in alphabetical order. Let me know if your choice is missing.
http://www.opinionpower.com/Surveys/929021270.html

Thanks for that; I'd say the results so far show what people reading this discussion (if not necessarily posting) really think. Perhaps you can provide a link direct to the results, so people who haven't read all the discussion can see the results without having to vote?

[Steve Bright]

Haven't read all the posts but am I the only one who thinks: "INSUFFICIENT INFORMATION"?
Lots of lovely hypotheses but all untested and untestable.
What I see is:
1. a 'streak on the' picture which appears to terminate at the dark horizon, which may well be an artifact arising form any number of causes;
2. A bright flash, not clearly related to (1) which is probably a reflection of sunlight from glass or metal at the top of the pole, or a more distant source on the water's surface;
3. Some mist or smoke which appears to be rising from a source hidden behind the bushes adjacent to the pole, probably unrelated to (1) and (2), (although it appears to be diffusing the flash, supporting the idea of a more distant source for the flash.

[Ruben]

Taking the photo at prima facie, it appears as though either a streak of some type of energy came from the heavens and struck the pole or that the light pole sent a streak of unknown energy into the heavens. This would be the most exotic interpretation of what happened and the least explainable. The most likely happenstance is that it is the occurrence of two common events: a contrail or a streak of something flying by at close range and a light bulb burning out or a short of some sort.

I don’t think it was a blur of something flying/gliding by for a couple of reasons: 1) It simply doesn’t appear to be such a streak as one would think that this would leave a telltale streak and not one that just so happens to look like a contrail. One could test this fly-by theory by simply attaching a small, buggish object to a fishing line and sending it at different bug speeds past a camera with identical settings as the original and trying to get it to produce such a streak. My bet is that such a streak will not be produced (a streak will be shown but certainly not in a manner characteristic of a contrail). 2) If it was an insect/bird, it is quite remarkable (unbelievable, frankly) that it flew in such a direction and at such a speed in relation to the camera lens that it produced a uniform streak as the one seen in the photo.

The bug theory seems plausible since it would explain the streak showing up in only one photo, and it rules out aliens and so forth; however, bugs don’t produce streaks like that. Jet aircraft fly above clouds and their attendant weather, and in that one particular picture, the Sun’s rays struck the contrail just right for it to show through the clouds as a long, dark, straight shadow. I don’t think that this is too difficult.

[Cloudbait]

Haven't read all the posts but am I the only one who thinks: "INSUFFICIENT INFORMATION"?
Lots of lovely hypotheses but all untested and untestable.

Just because there is insufficient information to interpret the image with 100% certainty doesn't mean that various interepretations can't be discussed. Some are testable (e.g. a fairly simple experiment can determine if a small object moving in front of the camera can produce a dark streak), some can be discarded on the basis of physics (meteors and contrail shadows), and some can be evaluated from physical evidence (the wharf and light fixture have been examined).

Do you think that JPL should stop trying to interpret their planetary images? Talk about insufficient information!

[hazeii3]

Is it just me or does it appear that there is a slight arc to the streak?

Maybe I see something. I used the measuring tool and see something pulsing every 121 pixels. Can FFT guy identify 121 pixels on his chart?

The trail is clearly not straight; here's an enhanced version, rotated -33.6 degrees to make it approximately horizontal, and with a 10:1 compressed version shown on the left.


(Click on image for larger version)

Ref. a pulse at 121 pixels (thinking out loud here), the trail length is around 1150 pixels in 1/20th second, equal to a sampling rate of 23000hz. So 121 pixels is about 190hz - which is pretty good for an insect wing beat. (anyone got data on likely australian flies?). You can estimate where 190Hz is by scaling back from the marker signal at 3125hz (i.e. it's about 1/16th of the way along the X axis between the origin and the marker) and now you mention it I can see a hint of something in that area of this image. Trouble is, it's very easy to see what you want to see in this kind of situation; and while I can see a possible signal at 190hz, the thing is it should not appear in the middle bins (in the middle distance of the image) since that's where the body trail is, or at the front or back (since the FFT's here are outside the evident wingspan). I'll focus on that area though, and see if anything pops out.

[Guest]

Meh so what if I live in Darwin where this happened.

It certainly wouldn't have been a gunshot as there were no reports and that area is fairly busy with people during the day. Personally to me for something that size it'd have to be a railgun or similarly stupid weapon. Read: Not yanks, it is even more unlikely that someone who have a gun than a meteorite hit.

The light fittings were damaged.

We don't have aircraft usually come around that direction, rather behind the camera's position parallel to the wharf seen. Also to the fact that the contrail isn't there before/after.

If it was a meteorite it would have been travelling 300,000km/h roughly most likely a grain of sand. Do the maths at what sort of a energy that would create regardless and how straight a line it would create. Before I saw this thread it looked like a typical impact blast dispersion pattern.

Oh and you guys have all the wrong bees.

[Guest]

Is it just me or does it appear that there is a slight arc to the streak?

Some have suggested that, but if you load shot #2 into drawing software and draw a straight line along the path, the streak is very straight. Look at the blinking (certainly straight) line on this rotated crop of the diff image:

Reality check everyone. It's a bug. This diff resolves the issue for me -- although I've been hoping all along for something more exciting. (*sighs*)

[victorengel]

I've created a survey. The software allows only 10 entries. I put them in alphabetical order. Let me know if your choice is missing.
http://www.opinionpower.com/Surveys/929021270.html

Thanks for that; I'd say the results so far show what people reading this discussion (if not necessarily posting) really think. Perhaps you can provide a link direct to the results, so people who haven't read all the discussion can see the results without having to vote?

Unfortunately, it looks like some cowboy has shot holes in the pole. But here's the link. For the record, the last time I checked, the score was 21 to 0 for the insect.
http://www.opinionpower.com/results.cgi?id=929021270

[victorengel]

Ref. a pulse at 121 pixels (thinking out loud here), the trail length is around 1150 pixels in 1/20th second, equal to a sampling rate of 23000hz. So 121 pixels is about 190hz - which is pretty good for an insect wing beat. (anyone got data on likely australian flies?). You can estimate where 190Hz is by scaling back from the marker signal at 3125hz (i.e. it's about 1/16th of the way along the X axis between the origin and the marker) and now you mention it I can see a hint of something in that area of this image.

Instead of making a 3d graph, why not make a sum or mean from front to back of that graph? That should help to eliminate some of the noise.

[Guest]

[qote="Anonymous"]

...if you load shot #2 into drawing software and draw a straight line along the path, the streak is very straight. Look at the blinking (certainly straight) line on this rotated crop of the diff image:

Quite the oppostive in fact, that line clearly starts in the centre of the trail and even accepting it does actually end in the trail centre, in the middle of the image the line appears to drop below the trail centre. Pretty clear evidence for an upward bend in the middle just like others have been saying.

[Guest]

Haven't read all the posts but am I the only one who thinks: "INSUFFICIENT INFORMATION"?
Lots of lovely hypotheses but all untested and untestable.
What I see is:
1. a 'streak on the' picture which appears to terminate at the dark horizon, which may well be an artifact arising form any number of causes;
2. A bright flash, not clearly related to (1) which is probably a reflection of sunlight from glass or metal at the top of the pole, or a more distant source on the water's surface;
3. Some mist or smoke which appears to be rising from a source hidden behind the bushes adjacent to the pole, probably unrelated to (1) and (2), (although it appears to be diffusing the flash, supporting the idea of a more distant source for the flash.

Just because we don't have enough information doesn't mean we don't know what this is... gee whiz, we have everything we need... a mysterious streak that OBVIOUSLY has to be a gamma ray from the center of the Pultonorian Galaxy, and a bug that flys in front of a vaporizing streetlight... what else do we need to know for sure... it's plain a day!!!!

[JBL]

I do graphic analysis and have an answer.
The three photos are related. The first contains no contrail or other evidence of an event. The second, containing the 'contrail' and 'flash' has similarities that can be seen in the last picture, though not readily evident. Typically, a burning contrail produces after effects that linger in the atmosphere but can be difficult to detect if one is 'down-light', or, what you are trying to see is between you and a light source. Still, smoke contrails disspiating change colors and shifts to greys and blues from this vantage point. The last photo still has traces of the contrail though faint. This eliminates a shadow caused by a pole or light housing. It also eliminates a simple bug, bird, or hair on the lense since the background light has not changed. With the evidence still in the air in the last frame, and the flash gone, a dissipating contrail is the remaining cause. This also eliminates lightning as the cause, since lightning does not leave contrails of smoke in the airr.

[Ruidh]

I do graphic analysis and have an answer.
The three photos are related. The first contains no contrail or other evidence of an event. The second, containing the 'contrail' and 'flash' has similarities that can be seen in the last picture, though not readily evident.

No one has demonstrated anything in the after image yet. Do us some image processing before the before and after pictures and show us the similarities you're talking about. Remember that the picture labelled "after" on the APOD page is actually the before and vice versa.

[Guest]

Government project.

[Dickison]

Is the flash really a flash or is it a plume of water from whatever it was hitting the water directly in back of the pole? The apparent smoke may be merely coincident.

[Guest1]

The bug theory just doesn't cut it for me right now. I say it's a government project.

That's got to be about the funniest and most absurd thing I've yet to read on this board.

Thank you for making me laugh out loud.

It wasn't meant to be funny. You're sense of humor is appreciated but not valid.

[Guest]

It's probably not necessary now that other people have done fancier analysis like FFTs, but I would think a better indication would be to sum/normalize/replicate the pixel rows parallel to the body trail. This might average out the noise but leave dimmer bands parallel to the trail with each wing beat.

I'm not clear what you're suggesting....because you mention wing beats,are you suggesting summing the pixels perpendicular to the trail? It's certainly a nice idea - I tried it, and took an FFT of the result (btw, the other FFT stuff was me too) However, there was still no sign of a periodic signal. Possibly a better approach would be to take the FFT's of the pixel strips first and then sum the FFT's; that way any phase difference between the strips wouldn't affect the result. Essentially, it would be equivalent to lengthwise summing of the data in the following image (which is a 3D representation of the FFT's of a 200-pixel strip centred on the trail).



(as usual, click the image for a larger version, and see here for further info)

The actual expected signal would be similar to the various 'rod' photographs others have posted (e.g. the top pic on this page. Just out of curiousity, I'll try an FFT on those pics tomorrow and see what appears; I'd certainly expect a strong signal from them.

Yes, I meant perpendicular. Geez, I screw up the most important word in the posting.

And I agree that the result might look sort of like the "rods" people capture with video cameras.

[victorengel]

I do graphic analysis and have an answer.

Good. Then you can use your expertise to SHOW us. By the way, since the first and last photos have been confused, it would help to clarify which you're really talking about. More than once someone has claimed a lingering effect in the last photo when the photo they really were talking about was the first.

Typically, a burning contrail

What is a burning contrail?

The last photo still has traces of the contrail though faint.

Please show us where using something other than an animation.

[Marspainter@optonline.net]

I too saw such a streak last week.
While traveling on interstate 81 north from Florida to New York, I saw the dark streak from clouds to earth. I looked and looked and asked my husband if he could see it too. He was driving, saw it and commented he did not know what it was. Never have I saw such a thing. It was December 2nd or 3rd, west north west about 10 o'clock in the sky. We were probably traveling thru the lower southern states at the time.

[dimwit]

Beats the hell outa me. But, i'd like to think it was a piece of space junk falling to earth... a simple and harmless explanation I know, but nonetheless, bette rthan the possibility of a pieceof space paraphenalia abbout which we know nothing, which now lies buried, waiting to assume its proper form and emerge triumphant to take over the planet.

[Rob]

I think you may have discounted the ray and reflection theory too lightly. The angle to the sun from the flash is close to 90 degrees or at 3.0clock to the angle of the camera. Note the light on the far shore to the right is in two pictures but not the third. I know the pictures are labelled wrong. the barge in the background has a nice reflection projecting from the front. Gunshot or blast are out because there is a manned security gate 30 or so yards from the light. Nobody heard or reported a thing. The light was inspected and found all good eccept for the globe blown but not damaged. Darwin has a 28 ft rise and fall of the tide. A small ship could easily have started its engine to create the light and the smoke and still remain hidden behind the wharf. The work you are doing on the bug theory is good however bug wings are very reflective and should not look like smoke. Nearest bug we have in darwin is a large termite very active this time of year after rain and just on sunset called mastotermes darwiniensis. Shape and colour are good and wings are twice as long as the threequarter inch body. Mud wasps also fit the bill and come in several colour shades and size

[RL]

In the small photograph, you only see a small portion of the image.

Look at the enlargement.

Track it from lower right to upper left.

You will see that where it begins is not straight.

It began as a fork, that melded into what appears to be a straight line.

What is it? An ionization discharge.

RL

[Guest]

The shortest exposure time on this camera is 1/2000 s.
So it seems very reasonable to assume that the flash
is shorter than this. It could be difficult to determine
the exact length of the flash for this picture, because
many modern cameras vary the length of the flash depending
on the amount of reflected light.

Electronic flash times are typically in the range of 10s of microseconds to a few milliseconds. Since you can't control the brightness of the flash directly, you control the flash time. In this case, the camera reports that no flash return signal was detected, which may mean that the maximum time was used (since there would be no brightness feedback). Unless someone can decode some of the more camera specific data (like the value for FLASH of 89) I would assume a flash time of 1mS to be reasonable.

======
Still no info on the flash? If it was ~1ms indeed the bug theory can be ruled out due to absence of the bright spot blurring.

[PopeyeBubbleHead]

One reader posted...

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

I tend to agree with this.

[victorengel]

Still no info on the flash? If it was ~1ms indeed the bug theory can be ruled out due to absence of the bright spot blurring.

Unfortunately I can't find much information. Without information, the best guess is a maximum of 1/1000 second (which would work out to a blur of about 24 pixels or so). The specs say the flash range is 0.7m to 5m. If 1/1000 second is the longest possible duration, this would make the shortest possible duration 1/25,000 second (which would work out to a blur of 1 pixel).

In any case, unless the data is somehow imbedded in the jpeg, I don't think we have any way of knowing what duration the flash was.

My guess is that the flash was pretty short, or else we'd see some evidence of the flash on the vegetation in the foreground.