Discussion of APOD 15 August 2007: Mysterious Streaks

Comments and questions about the APOD on the main view screen.
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RJN
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Discussion of APOD 15 August 2007: Mysterious Streaks

Post by RJN » Tue Aug 14, 2007 5:04 pm

Last edited by RJN on Wed Aug 15, 2007 9:42 am, edited 1 time in total.

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Re: Discussion of APOD 2007 August 15: Mysterious Streaks

Post by Andy Wade » Tue Aug 14, 2007 5:36 pm

Reflections from a satellite/s? Or even aeroplanes?
Could these could be 'glinting' from the reflective surfaces?
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Post by iamlucky13 » Tue Aug 14, 2007 5:36 pm

My first thought was a broken up meteor, just like they suggested. I was thinking it was a little funny to see them all together like that instead of strung out in a row, but it was a long exposure image, so these probably were strung out and entered nearly the same spot of the atmosphere at different times during the exposure.

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Re: Discussion of APOD 2007 August 15: Mysterious Streaks

Post by Chris Peterson » Tue Aug 14, 2007 7:33 pm

RJN wrote:What are they? Thoughts?
Normally, when you see short streaks through Orion they are geosynchronous satellites. But in this case, the direction of travel is too far off the ecliptic, and the angular speed is too great (assuming each streak was caught in a single 105-second exposure).

Supposedly, these five images are composited over 40 minutes of exposure time, which is enough that I'd expect them to be somewhat less parallel if they share a radiant. I don't know where the stellar background is from, either- it obviously isn't a stack of 5 images over 40 minutes (unless the images were aligned on the stars, and the background only shows up in the final, near-dawn image). If all the streaks were following the same path, they should be about 10° apart from first to last in 40 minutes, but are actually only about 5° apart.

I did a great circle analysis on the second streak from the top, and it intersects the Alpha Ursae Majorid radiant (which itself isn't precisely defined) to within 24 arcminutes- a strong argument for association with that shower, although I can't imagine why you would get 5 events in 40 minutes, happening so close together. Very odd.
Chris

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What are they?

Post by DomeLiving » Wed Aug 15, 2007 4:21 am

If this was 10 years ago I'd say it was scratches on the negative. But, since the photo is most likely from a digital camera, darkroom particles are probably not the reason.
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Post by craterchains » Wed Aug 15, 2007 4:26 am

Below is the equipment listed at this photographers site.
With the barn door drive he can do a 40 minute exposure. Where Chris comes up with the idea of stacking is news to me, and not listed about the image. (Copied below also.)

Telescope
Meade 8" LX10 SCT
.
Cameras
Canon EOS 300D (Digital Rebel) SLR
Zenit 12XP SLR (for really cold conditions, my first camera since 1993)
Pentax Spotmatic SLR
home-made medium format all-sky camera,
home-made barn-door drive (since 1996).
Philips TouCam Pro 740 webcam
.
Software
Adobe Photoshop 6,
Grasshopper's ImageAlign 1.2.1


Mysterious Streaks Over Turkey
Credit & Copyright: Tunc Tezel

Explanation: What are they? Five streaks near the bottom of the above image taken near Ankara, Turkey on Sunday would be identified at first glance as meteors from the Perseids meteor shower peaking just that night. Unexpectedly, however, these streaks do not point back to the Perseids radiant in Perseus. Their origin is therefore somewhat unclear. The above image was captured over the time span of 40 minutes. Other visible celestial icons include the constellation Orion and the Pleiades star cluster. One hypothesis is that the streaks are part of a microburst from a much less active meteor shower known as the Alpha Ursae Majorids. Another possibility is that they are parts of a satellite that broke up as it re-entered the Earth's atmosphere. A discussion of these possibilities can be found here. This year's Perseids meteor shower was a good one, as it was particularly active and corresponded with the dark skies that come with a new moon.
Authors & editors: Robert Nemiroff (Our very own RJN above) (MTU) & Jerry Bonnell (USRA)
NASA Official: Phillip Newman

What is obvious, or apparent;
1. Is that we the public, are being asked by the professionals, what made these streaks? Interesting.
2. Most likely the professionals have ruled out the obvious based on certain known facts.
3. Chris has added information that is either true, or a fabrication? Confusing.
4. Dr. Nemiroff presents the photo in question. :!:
5. Tunc Tezel should be given better equipment for his efforts. :wink:

This 40 minute exposure captures 4, or more streaks that were moving across the image, think about it based on brightness durring that 40 minutes. :idea:

Norval
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Post by Chris Peterson » Wed Aug 15, 2007 4:42 am

craterchains wrote:Where Chris comes up with the idea of stacking is news to me, and not listed about the image.
The same image was submitted to Spaceweather.com with the following comment:

I took a 100-picture series of 105-second wide angle pictures using a Canon EOS 300D camera at ISO1600 and a 10-22 mm lens at 10 mm f/3.5, looking east. In 3 hours 20 minutes that I took the pictures, I recorded 12 Perseids and 9 others. Close inspection showed all these 9 to be possibly originating from Alpha Ursae Majoris, source of an otherwise weak shower. I want to submit this composite picture of 5 bright Alpha Ursae Majorid meteors striking Orion in less than 40 minutes' time.

I surmise that the composite was made from five of these 105-second exposures, but don't know that for sure. There's no indication that a tracker was used, and you can't make a single 40-minute image with a Canon 300D in any case. The image metadata shows that the image was processed with Photoshop 7.
Chris

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Post by Asi » Wed Aug 15, 2007 4:46 am

Broken up satellite or other human made space debris would be my guess.

Has anybody checked the date/time/location of the shuttle main fuel tank reentry?

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Post by craterchains » Wed Aug 15, 2007 4:47 am

Tips his hat, muchos grassiess Chris. :D
Will think on that information as fact for now then. And, check up on it too. :wink:

The plot thickens a slight bit me thinks.
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Post by skysat » Wed Aug 15, 2007 5:15 am

This looks very much like a series of Iridium flares. Unfortunately, neither the location nor the time is given with precision. However, Heavens-Above reveals two flares for Ankara on two dates.

Iridium 5 12 Aug 00:42:09 UT
Iridium 8 13 Aug 00:35:49 UT

The track for both of these matches the brightest track in the photo. Since Iridiums follow each other by 9 minutes (as I recall), the offset tracks would be other Iridiums in the same plane producing minor flares not reported by Heavens-Above.

Randy

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Re: Discussion of APOD 2007 August 15: Mysterious Streaks

Post by Qev » Wed Aug 15, 2007 5:19 am

Andy Wade wrote:
Reflections from a satellite/s? Or even aeroplanes?
Could these could be 'glinting' from the reflective surfaces?
I was wondering the same thing, if these could be light streaks on the lens itself caused by car headlights or something similar, traveling past outside of the field of view. As the camera moves to track the sky, each successive streak would, on the final image, seem to be in a higher (or lower) position than the last.

Also, what are the coloured dots on the hill in the foreground? Images of stars superimposed on it as the camera tracks the sky?
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http://antwrp.gsfc.nasa.gov/apod/ap070815.html

Post by lilcesar » Wed Aug 15, 2007 6:02 am

if u look close at the top of the hill, it looks like there is a light being pointed upwards in the sky, the streaks of light Resembles a light being pointed at power lines , another thing that cought my atencion is the blue , red and some very faint diferent color dots in the hill when you zoom in to it.could this experts be trying to pull a trick on us just to see what we would say about the picture.

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Spacing of streaks

Post by traveller » Wed Aug 15, 2007 6:30 am

Looking at the column of pixels 1160, the streaks are at vertical pixel positions 663, 654, 642, 622, 594, starting at the bottom. These form quite a regular progression. Although we have no information (as far as I know) about the timings, it seems to me that this would be most unlikely for a break-up of any sort. I find the idea of Iridium twinkles more credible.

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Post by Jeffsut » Wed Aug 15, 2007 7:37 am

OK, Can someone please tell me how this guy can take a 40 minute guided photograph and still get the sky and foreground mountains pin sharp or it it a composite image. He must be pretty far away from Ankara to get a dark sky like that.

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Post by bilious » Wed Aug 15, 2007 10:01 am

Chris Peterson wrote: I surmise that the composite was made from five of these 105-second exposures, but don't know that for sure. There's no indication that a tracker was used, and you can't make a single 40-minute image with a Canon 300D in any case. The image metadata shows that the image was processed with Photoshop 7.
Hi guys, just signed up to comment on this.

Firstly, the 300D can do an 'unlimited' length bulb exposure. (The manual actually reads "With a fully charged battery a single bulb exposure can be as long as about 2.5 hours," presumably the limitation is battery capacity.) However, of more salience is the EXIF info pulled out of the photo from the APOD site:

(Cut down for brevity)
Make - Canon
Model - Canon EOS 300D DIGITAL
Software - Adobe Photoshop 7.0
DateTime - 2007:08:13 19:14:11
ExifOffset - 220
ExposureTime - 56 seconds
FNumber - 3.50
ISOSpeedRatings - 1600
DateTimeOriginal - 2007:08:12 04:28:23
ApertureValue - F 3.50
Flash - Not fired
FocalLength - 10 mm

So it was a photo of about a minute's exposure at ISO 1600. Evidently as the description talks about a 40 minute period, these 5 incidents come from different exposures blended together in Adobe Photoshop.

As to what they are, they are not of complete uniformity either cf one another, but also not across the length of their appearance. The 300D has pretty weak buffer/write so there can be enormous gaps between each exposure (upwards of 30 seconds for some long exposures) which explains why the second from the bottom looks like it simply appears at full intensity.

My guess, meteors, but I'm much more of a camera nut than a space nut.

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Re: Discussion of APOD 2007 August 15: Mysterious Streaks

Post by LIVbase13 » Wed Aug 15, 2007 10:39 am

Andy Wade wrote:Could these could be 'glinting' from the reflective surfaces?
Yes, it could indeed. I'm fairly certain it's satellite flares.

The picture below is a confirmed shot of a -8 flare made by Iridium 65. The much smaller flare is made by an unknown satellite, and occurred approx. 1 min before the Iridium flare. There are also a microflare on the picture (though hard to see in this web-friendly pict.) just above the Ir-flare. It's either another satellite or more likely a reflection in another part of the Iridium satellite.
Image

Many of the satellites passing thorugh this part of the sky, at this time would if seen from my position produce flares - in a 40 minutes periode, there could be quite a few, and I'm convinced that's what's going on on the APOD-picture.

Image
Last edited by LIVbase13 on Wed Aug 15, 2007 10:43 am, edited 1 time in total.
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Post by avicenna » Wed Aug 15, 2007 10:39 am

Hello, I am an absolute beginner so please bear with me.
It is just that I did see one of those mysterious streaks too.

From The Hague in The Netherlands, ( that is about 52 North)
the morning of August 12, somewhere between 03.00 and
04.45 am (local time, so I guess that would 01.00-2.45 GMT)

I have a large wedge of sky that I can see from my 10 mtr. balcony,
facing east and quite a bit of south. I was watching in the general direction
of Perseus and saw a few meteorites coming in. Then there was this streak coming in from the right (the southeast) and going to the left (east), and perfectly horizontal.

I was surprised at first then I thought, hey, I am new at this game, so why not?
I did not take any pictures (haven't got a good camera yet) but I can state that

a. it was a streak that moved horizontally from right to left
b. it didn't twinkle
c. there are no powerlines in all of my sky
d. this was above the pollution line that hinders a lot of my viewing

So?
Annemarie

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Post by LIVbase13 » Wed Aug 15, 2007 10:50 am

avicenna wrote:It is just that I did see one of those mysterious streaks too. [...] Then there was this streak coming in from the right (the southeast) and going to the left (east), and perfectly horizontal.
If you saw a streak, it was properly the trail of a plane.
Flares are seen as dots where the light grows stronger, culminates, and fade to nothing again, whilst moving across the sky. In a long exposure picture, this will form a streak. To the naked eye it'll look like a "moving star"

Kind regards LIVbase13
Last edited by LIVbase13 on Wed Aug 15, 2007 10:53 am, edited 1 time in total.
Image-It's a matter of perspective...

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Too much words for nothing..

Post by MaG » Wed Aug 15, 2007 10:53 am

When someone said. They are Iridium flares. Not only Heavens-Above show me for this day Iridium flare in Orion, but Calsky, better for this, too.

So, for Ankara, 13. August 2007, there are these Iridium flares (on the image from bottom to top):
Iridium 6, 0:16:16 UT
Iridium 51, 0:24:45
Iridium 7, 0:25:31
Iridium 8, 0:34:49
Iridium 4, 0:44:07

So what you saynow? ;)

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Electrickery wires

Post by Craine » Wed Aug 15, 2007 11:13 am

This may sound strange, but I believe the streaks may be a set of electrickery wires running across the field of vision, with the supporting poles out of sight. The light from the bright source near the horizon at the bottom right may be reflecting of the wires.

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Streaks hypothesis

Post by progan01 » Wed Aug 15, 2007 11:31 am

I was all set to accept MaG's Iridium flare explanation, then I checked the orbits via NASA's JTrack (http://science.nasa.gov/Realtime/JTrack ... ack3D.html). All the listed Iridiums are in polar orbits. That does not explain these west-to-east streaks. If they are satellites, they are not the Iridiums MaG noted.

The bottom three streaks do show the characteristics of an Iridium flare, suggesting a brightening from an aligned reflective surface on the satellite. They are also characteristic of a meteorite burst. I tend to think now that this may have been five, possibly six objects traveling parallel paths, perhaps an object that broke up before it entered the atmosphere. We saw this behavior in comet Shoemaker-Levy before it struck Jupiter. Could this be a similar, smaller chain of debris from a single broken meteor?

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Post by agoronda » Wed Aug 15, 2007 11:36 am

Ok, I have been studying the picture for a little while. It looked a bit stupid, but since the last reply posted had my same opinion, this is my guess:
The foreground on the bottom right, the black part is the roof of a house or something like that. There are two strange sticks on the border of the roof, one on the right, not illuminated, and one next to this one on the left illuminated by a supposed source of light under the roof and pointing in the direction of the misterious lines. Those lines are just a spider web that comes from the tree on the left..... heheh
Ok, I know this is really a big imagination, but for me could be possible....

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Re: Electrickery wires

Post by LIVbase13 » Wed Aug 15, 2007 11:44 am

Craine wrote:This may sound strange, but I believe the streaks may be a set of electrickery wires running across the field of vision, with the supporting poles out of sight. The light from the bright source near the horizon at the bottom right may be reflecting of the wires.
But in that case the brightest points should be directly above each other, shouldn't they? The top one is far off to the right.
- And the second from bottom (the brightest one) ends very abruptly. It's exatly how a faild flare shot looks when you've missed half the action:

Image

If it were wires the light would fade out evenly on both sides.

Kind regards LIVbase13
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Post by skelley » Wed Aug 15, 2007 11:45 am

ALIENS!!!!!!!!!!!!!

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Post by quarkcsj » Wed Aug 15, 2007 12:01 pm

bilious wrote:
Chris Peterson wrote: I surmise that the composite was made from five of these 105-second exposures, but don't know that for sure. There's no indication that a tracker was used, and you can't make a single 40-minute image with a Canon 300D in any case. The image metadata shows that the image was processed with Photoshop 7.
Hi guys, just signed up to comment on this.

Firstly, the 300D can do an 'unlimited' length bulb exposure. (The manual actually reads "With a fully charged battery a single bulb exposure can be as long as about 2.5 hours," presumably the limitation is battery capacity.) However, of more salience is the EXIF info pulled out of the photo from the APOD site:

(Cut down for brevity)
Make - Canon
Model - Canon EOS 300D DIGITAL
Software - Adobe Photoshop 7.0
DateTime - 2007:08:13 19:14:11
ExifOffset - 220
ExposureTime - 56 seconds
FNumber - 3.50
ISOSpeedRatings - 1600
DateTimeOriginal - 2007:08:12 04:28:23
ApertureValue - F 3.50
Flash - Not fired
FocalLength - 10 mm

So it was a photo of about a minute's exposure at ISO 1600. Evidently as the description talks about a 40 minute period, these 5 incidents come from different exposures blended together in Adobe Photoshop.

As to what they are, they are not of complete uniformity either cf one another, but also not across the length of their appearance. The 300D has pretty weak buffer/write so there can be enormous gaps between each exposure (upwards of 30 seconds for some long exposures) which explains why the second from the bottom looks like it simply appears at full intensity.

My guess, meteors, but I'm much more of a camera nut than a space nut.
This guy's got it pretty close.
I was able to pull the data from the picture and got
56 seconds f/3.5 @ ISO 1600.

I have been shooting with a 300D since 2004.
The red and blue dots someone metioned before is hot pixels on the C-MOS, this is why we do dark frames to subtract these from our images.

And yes, you can take a 40 minute exposure with a 300D. Although at ISO 1600 it would be almost white from being over-exposed and the Hot Pixels would be outrageous.
I commonly shoot 2 minute exposures using DSLR Focus and stack them.

I learned that there are so many satellites running through that area of Orion, that I usually have to throw away a couple of images because of these streaks.

http://aisig.sdaa.org/astroblogDetail.a ... &UserId=54

Looking at a planetarium program and the position of Orion it looks like this was taken just before astronomical twilight which is the best time to see many satellites as the Sun lights them up just before rising.

It seems pretty obvious to me that these are satellites.
Thier tracks are parellel.

This image does not look like it has been Stacked.
The foreground if very sharp. And there is a little bit of trailing of the stars which would take a bit of time for such a wide angle shot.

If it was taken on a guided mount then the foreground would be blurred.

If 5 images were Stacked, registered on the stars, the foreground would also be blurred in that case.

Also the Hot Pixels would form a nice little 5 dot line if 5 images were stacked on the stars.

This really looks like a single image, either 105 seconds as mentioned, or 56 seconds as the EXIF data reveals.

In that case, it is really remarkable that you would get 5 satellites in such a short time.

Carey Johnson
Honolulu, HI