I'll give it a shot:
A small piece of caked ice breaks off of the shuttle near the camera port, and floats away from it. The shuttle, meanwhile, is still maneuvering around MIR; very subtly, because station keeping in orbit is a very subtle activity. At some point, the pilot slightly changes the velocity of the shuttle. The ice particle, which is perhaps now 5 - 10 m away (very much closer to the camera than MIR), seems to change direction. However, as the change in velocity of the shuttle is perhaps a few cm/s, our position relative to MIR does not change perceptibly.
What do I win?
You win my appreciation and respect for having a go and putting forward an ostensibly rational and plausible account of the object. I actually think this account is more plausible than the satellite account. The trajectory simply changes too much for it to be a satellite.
So let's work with this account and follow the trajectory and see if it can be reconciled.
Referring back to the diagram here:
[qimg]http://www.internationalskeptics.com/forums/picture.php?albumid=574&pictureid=3660[/qimg]
Figure 1: NASA 1995 STS74 3D trajectory diagram.
We must first draw the conclusion that between points a and b, the object is travelling away from us (because it appears to be slowing down when, if it were a piece of ice, then it could not
actually be doing so).
Now, what happens between points b and c? According to the hypothesis put forward by H’ethetheth it must mean that the shuttle has manoeuvred (rotated) upward. Given that we know the shuttle is already rotating upward (shown by the movement of the background stars) this would represent an increase in the speed of that motion. The question then becomes: To confirm this, is it reasonable to suppose this motion would be reflected in the motion of the background stars? In other words would that increase in speed of the shuttle’s rotation be reflected in a corresponding increase in the speed of the stars “drifting” down the screen, or is it too small a change to be seen?
Obviously, to answer this question, we will need to measure the rate of drift of the background stars. If we notice an increase in the rate of drift, that would act to confirm the hypothesis to this point (or at the very least it would not negate it).
But before we do that, let’s get a conceptual picture of the rest of the trajectory with respect to the “ice debris” hypothesis.
What then happens between points c and d? That trajectory change must mean that once again the speed of the shuttle’s upward rotation has increased (remember the
true trajectory of the object maintains a straight line trajectory at some angle away from us).
The object then halts all observed motion at point d. What does this mean in terms of the shuttle’s motion? First it
must mean that the shuttle has begun rotating from right to left and in so doing has
perfectly matched the object’s observed right to left momentum (let's leave arguments concerning the plausibility matching of various momentums aside for now). Second, at the same time, the upward rotation has slowed down to return to that speed it was between b and c (when the object was travelling parallel to the bottom of frame).
This would mean that at point d, the background stars
must begin moving left to right at a greater rate than they have been doing to this point.
Then what happens between d and e once the object resumes motion? Obviously the upward rotation of the shuttle increases speed again to (approximately) what it was between c and d while the right to left rotation is maintained.
Before we take measurements to see if we can confirm all of that, one other thing is particularly noteworthy. The object is receding from us at a set rate. However, once it reaches point b, it no longer appears to be doing so. That is, the intervals (as measured here [qimg]http://www.internationalskeptics.com/forums/picture.php?albumid=574&pictureid=3661[/qimg]) remain pretty much constant – or even in fact
increase and then
decrease again between c and d. What can
this mean in relation to the shuttles motion? That the object is no longer receding? That cannot be it - for example between points d and e the object is
obviously still receding – so much so that it actually disappears beyond the limits of camera resolution (somewhere about point e).
Okay, if the object is still receding, then how can we reconcile that with the shuttle’s motion? At point b the shuttle must also then begin to move forward (into the picture).
Good, under the “ice particle broken free from the shuttle” hypothesis, we
can then reconcile the trajectory of the object with the motion of the shuttle.
What remains is to take the appropriate measurements to see if we can confirm these motions.
Note: Jocce has previously asked for measurements to be taken, but before we had a hypothesis to work with, we did not know what measurements
should be taken or what any measurements that might be taken would be telling us. This is why I persisted in a conceptual framework until we had a plausible hypothesis to work with that we could either confirm or refute by taking specific measurements.
Of course the first hypothesis put forward here was that the object was actually receding from us and measurements of the object’s relative velocity were then taken.
For the satellite hypothesis, no measurements were needed beyond what could be directly observed because the trajectory of the object simply could not be plausibly reconciled with that hypothesis.
Returning now to the “ice crystal” hypothesis and the conceptual understanding of the shuttle’s motion as outlined above, the most relevant measurements to take would obviously be related to the motion of the background stars, for any change in rotation of the shuttle should be reflected in their motion. It only remains to be seen whether the resolution of the film is high enough to allow the measurements required to be taken to the degree of accuracy needed.
Of course someone should check my conceptual formulation of the shuttle’s motion above to see if I have got it right. I
could be mistaken…
Nevertheless, when time permits I will undertake as an initial analysis the motion of the background stars and report back as soon as I have completed that task ( I suspect that 5 sec intervals will be too long and perhaps I will drop that to 3 seconds, 2 if the resolution allows).
My methodology will be to take snapshots from the video at the prescribed time intervals, then transfer them to Photoshop, measure the X Y coordinates of some prominent stars (Orion's belt drifting down the left of frame is a good candidate) and then plot those coordinates on a graph that I can post to the thread. This will obviously take some amount of time but I should be able to accomplish the task within a couple of days or so.
If anyone can see any flaws in my methodology or conceptualisations – or has relevant information about the video that I might have missed - I would appreciate their input at this point.