There is literally no way to estimate the distance of an unknown object using single photos without additional distance cues. That is why I think as many cameras on board spacecraft as possible should have stereoscopic capabilities. Using a steroscopic camera the distance to all these bits of debris could be estimated fairly easily.

This object could be a small, close piece of debris relatively close to the spacecraft- an irregular piece of metal foil, by the look of it, perhaps the size of your hand.

It probably isn't a piece large enough to track as a hazard or there would be a record of it, so it isn't a fuel tank, a toolkit bag or part of another rocket. If it were part of another rocket they would have taken evasive action and moved the spacecraft some distance away - probably far enough away for the obect to be invisible.

It isn't a space alien, as we don't get to see those pictures.

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New Orion's Arm Site . The Starlark . Against a Diamond Sky (OA Novella Collection) . OA Flickr set

Something tells me that not having stereoscopic capabilities for distance measurement is not an issue.

It might be the mission specs, activities, and ground tracking radar of in-orbit material that tells me, but that's just a guess.

Just because "we" don't know doesn't mean it's not known, or wasn't known at some time.

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Numbers are not case sensitive. (me)

NASA publishes the Orbital Debris Quarterly News. Here's the January 1999 (PDF, 1.2 MB) issue (no missing moon yet). Page 8.

"On the second EVA an insulation blanket also inadvertently drifted away."

But the 2nd EVA was on Dec. 9/10. Would the blanket still be near, more than a day later? EVA 3 was after the date entered in the database.

Well, we don't know yet if there's a record of it or not, and I guess we won't unless someone does the work for OP again.

Good point. As noted, evasive action was taken on an earlier day in the mission. It would be nice though to have some corroboration on how much spatial separation is wanted or required (and if that was always achieved around 1998).

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"Ignorance more frequently begets confidence than does knowledge" -- Charles Darwin | Meet the OOONG TOE.
"Your right to hold an opinion is not being contested. Your expectation that it be taken seriously is." -- Jason Thompson
'No, mad's when you froth at the mouf,' said Gaspode. 'He's insane. That's when you froth at the brain.'

But the 2nd EVA was on Dec. 9/10. Would the blanket still be near, more than a day later? EVA 3 was after the date entered in the database.

The rate of separation between the ISS and the blanket likely would've been very small. The blanket would be more subject to drag but it's still possible the blanket could've been within photographic distance a day or so later. I've looked at the images but they're simply too small for me to tell much about the object.

Just a remark on this post , because I have no time to do my home work.

I don't see what is wrong with this kind of reasoning and it is not circular at all because I don't start with the conclusion.

I see it like this :

There is something strange in the sky , it look like a craft (to me) , it looks like it is shape-changing , I don't know of any craft from this Earth which can change its shape like this thing , so it could be an alien craft.

SO is it an evidence of an alien craft ? May be ,but I don't know for sure. Some people of course can say "space debris" , but also without evidence.

There is one important difference between the two options: we have plenty evidence that orbital debris exists. We have no evidence that alien craft exist.

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"Ignorance more frequently begets confidence than does knowledge" -- Charles Darwin | Meet the OOONG TOE.
"Your right to hold an opinion is not being contested. Your expectation that it be taken seriously is." -- Jason Thompson
'No, mad's when you froth at the mouf,' said Gaspode. 'He's insane. That's when you froth at the brain.'

As someone who has spent decades studying aircraft recognition, I know from experience how different a plane can appear depending on the angle you view it. In the case of the object in the images, if it isn't stable and is tumbling, the shape will appear to be changing when what's really changing is the aspect. If it were something flexible like the speculated insulation blanket, then the shape itself could be changing as it tumbled and reacted to drag.

Indeed all visual perception is merely the interpretation of patterns of light and dark (color aside for a moment). Notions of shape are heavily informed by preconceptions of what some object may be, and in this case the belief that the object is not tumbling. Tumbling spent boosters "pulsate" because they change aspect as seen from afar. The viewer cannot see the outline, only the change in apparent brightness. Therefore it is tempting to interpret the object as something flying straight and level but pulsating inexplicably.

One of the central misconceptions of UFO fanaticism is that if an object were ordinary, it would be easily seen as such. That simply isn't true. Training and experience can improve one's ability to recognize objects in their non-canonical forms, but it does not elevate that skill to the point of ruling out a misidentification by someone's inability to recognize it as mundane.

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"Facts are stubborn things." --John Adams
Clavius Moon Base

So you're starting with the premise that, because it looks like it's changing shape, it is, and it's not because your eye is being fooled? Yes, that's much better.

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Gillian

"Now everyone was giving her that kind of look UFOlogists get when they suddenly say, 'Hey, if you shade your eyes you can see it is just a flock of geese after all.'"

"You can't erase icing."

"I can't believe it doesn't work! I found it on the internet, man!"

And yet you claim the expertise to identify a tumbling irregular shape as a shape shifting alien craft?

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‘To those who regard “crime fiction” as some sacred icon which must follow a rigid formula, I will always be the man who writes 18-syllable haiku.’Trying to make sense of computers, The Error Log.

Space debris is known to exist and to produce visual effects like this. Alien spacecraft are not known to exist, and therefore no properties about them can be rationally asserted. Hence to say the identification is "without evidence" is absurd. Your leap to consider it possibly an alien spacecraft is what makes your reasoning somewhat circular.

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"Facts are stubborn things." --John Adams
Clavius Moon Base

As you rotate a tetrahedron the face-on view can be an equilateral triangle or a square. How can a solid object look like a triangle or a square without changing shape?

As George Carlin noted, "It's a mystery."

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There is room for an existential shiver in the dark between the stars.

Most of the spurious UFOs that people see in the STS films are actually small pieces of ice, very close to the ship; these won't show up on logs or on radar.

But a stereo camera would eliminate a large proportion of them. Even with stereo cameras it is sometimes possible to get false positives, when two identical objects appear to be one larger one further away.

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New Orion's Arm Site . The Starlark . Against a Diamond Sky (OA Novella Collection) . OA Flickr set

Gillianren, thanks for that. You've articulated the basis of the point I was trying to make, albeit my post was written in a somewhat clumsier manner.

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There we were in the park when suddenly some old lady says I stole her purse..... I chucked the professor at her but she kept coming..... So I had to hit her with this purse I found.
-- Bender

In all sorts of areas of pseudoscience (relativity denial, UFOs, alternative medicine) we see this same dogmatic assertion that "I perceive X, therefore X MUST be true", and I do wonder what causes it.

When I hear Moby coming through my stereo, I know that he's not really performing inside there, but that technology makes it seem as though he is, pretty convincingly. In so, so many other ways, I know that what I "see" is not real. The sun does not orbit the earth, the room does not really spin when I am drunk, and two lines with arrows on the end;

<----------> >----------<

Are not really different lengths just because they seem to be so. Our senses are fooled all of the time. Our vision, and our memory of our vision, is not really anything like a video recording, it's a series of moving edges with the details filled in by the brain. There is a huge amount of processing, probably optimised for a life hunting on the savanna, so of course it throws up any number of false flags in the modern world.

Why then, when presented with an unusual stimulus, do the scientists tend to correctly accept that it might be an artefact of our processing ("It looks like shape changing, but that is as likely to be just rotating as anything else"), but some others say "I saw it change shape, it must therefore change shape, and therefore must be an alien spacecraft" when presented with the same sensory input?

You listen to Moby?

All respect I had for you as a scientist has been lost...

Heh heh. Moby, Coldplay, Keane, Slayer, Snow Patrol, Creed, Enya...

An eclectic, and very, very far from cool collection of tunes, I know.

And sadly, I'm no longer a scientist, just one more person who was lured from pure science and into banking some years ago, and who therefore chose the less noble path in pursuit of more base goals...

Oh, a banker... cool... cool... Yeah, banking is nice. But... It's not Brain Surgery.

Galasci- that is starting with the conclusion.
Not knowing what you're looking at and jumping to a conclusion; then telling others to prove you wrong- IS starting with the conclusion.

Yes; for us, not for the mission and specs.
They know that if it's that small and only spotted later on imagry, then it's of no importance. If it's large, then there's other tracking.

The stereo camera would be for our benefit, not the mission's benifit.

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Numbers are not case sensitive. (me)

But you know, how many popular musicians work physics references into their songs? Moby, in an interview, was asked about his song "We Are All Made of Stars." When asked if it was intended to be spiritual, his response was, "No, it's physics." Scientifically, Moby's the man.

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Gillian

"Now everyone was giving her that kind of look UFOlogists get when they suddenly say, 'Hey, if you shade your eyes you can see it is just a flock of geese after all.'"

"You can't erase icing."

"I can't believe it doesn't work! I found it on the internet, man!"

They Might Be Giants just released a CD/DVD called "Here Comes Science," as described in this article.

Nick

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--
Nick Theodorakis

One little nitpick. A regular tetrahedron always looks triangular from any angle, though its exact shape can vary somewhat. Face-on, every face is an equilateral triangle.

I believe the object you're referring to is the Square Pyramid, or possibly the Tetragonal Bipyramid which can be thought of as two square pyramids base-to-base.

Regardless, however, your point is perfectly valid -- most solid objects will appear to change shape as they rotate. A sphere is an important exception.

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Relight the Firefly!

"It is quite clear that Occam's razor does not sharpen in your pyramid." (Nicolas)

"Still, a man hears what he wants to hear and disregards the rest." (Paul Simon)

Okay, the obvious other choice! (I should go dig out my tape with the live version of the Sun song that I have around here somewhere.)

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Gillian

"Now everyone was giving her that kind of look UFOlogists get when they suddenly say, 'Hey, if you shade your eyes you can see it is just a flock of geese after all.'"

"You can't erase icing."

"I can't believe it doesn't work! I found it on the internet, man!"

One of the more dramatic examples of how the appearance of an object can change radically depending on the angle you view it is the now-retired F-117A Nighthawk.

From this angle, the plane looks rather fat. However, from this angle, it much more slender. Take a look at the series of NightHawk photos on this page. Other than retracting and extending the landing gear, the plane is not changing its shape but the appearance changes significantly.

See what the astronaut is holding (not the MMU!) in this drawing (found it while searching for the trunnion pin cover thingy). Imagine that thing floating away near ISS. With no indication of depth, it might well seem a huge thing far away, instead of a known small device close up.

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"Ignorance more frequently begets confidence than does knowledge" -- Charles Darwin | Meet the OOONG TOE.
"Your right to hold an opinion is not being contested. Your expectation that it be taken seriously is." -- Jason Thompson
'No, mad's when you froth at the mouf,' said Gaspode. 'He's insane. That's when you froth at the brain.'

You know what would be awesome? Dowload the HiRes pics, make a video of them, add some awesome music, and put it on YouTube!!

http://www.youtube.com/watch?v=6GDFDk39g58

How cool is that?

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Smile, and the Universe smiles with you. Frown, and everybody stays out of your way. And once, everything was a pie.

OK zooming in takes all the mystery out of it, but still ...

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Smile, and the Universe smiles with you. Frown, and everybody stays out of your way. And once, everything was a pie.

Grab yourself a tetrahedron and hold it so that one edge is directly facing you. While the vertices are at different distances from your eye, their 2-D projection is a square.

I just tested it with a blob of putty. I was pretty sure I was right.

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There is room for an existential shiver in the dark between the stars.

A blob of putty, or a shape-changing alien spacecraft?

Galacsi...I fail to understand what the advantages of a shape-changing spacecraft would be.

I mean, other than just a means of pigeon-holeing evidence to "fit" what is supposedly observed, to what benefit could it possibly be?