Obviously what we see in every movie or image, so, the same goes for this NASA videos, it is NOT the reality, but only a good or better aproximation
of it, in fact a REPRESENTATION. Every representation (copy if you want) of a phenomenon will describe real characteristics, but can introduce a
degree of ERROR (artifact). Those errors depends on technical and physical principles used to construct that representation. For understanding those
principles, is really a matter of how deep you want to go into ussually boring stuff.
Here in this NASA movie with the "meteor-like swimming" there, we have a lot of artifacts.
First, camera's are used in low light situation, so they are set toward their maximum posibilities, meaning selecting (automatic or manual) modes
suitable for low-light, like increasing electronic signal gain, maximum iris, maximum shutter speed etcetera, all of them selected to aquire more and
more light from where is not enough light.
The stretching of the posibilities to their maximum ALWAYS degrade the quality of the image (introduce visible artifacts). Think at your own camera or
photo-camera how made images/videos in extreme conditions of low light. Are they "perfect"? Why dark? why blurry, why crappy?
Here in NASA videos we have:
- more or less noise on the image
- blooming (overexposing and negativation) of the brigther zones
- image remanence (especially seen in faster moving objects) (i'm not so sure about the actual word, i'm not native english)
- artifacts due to interference from movement of the object and the method of aquirring image from the senzor (scanning lines of image one by one)
- sharpening artifacts (due to senzor/electronics)
- compression/recording artifacts (not talking by youtube compression artifacts, these are "bonus", but originalcompression/recording artifacts )
- or even other ERRORS
These errors EXIST and you, as a watcher, see them. But it is a mistake to ignore them, and to think that what you see is the reality itself.
Regarding the fast moving meteor-like object, my opinion is that it could be very well a closer particle of debris, going "fast" (in "angular
velocity" terms) in front of the camera (just like a bug zippingg through the frame).
The longer tail, is not real, but only remanence in the video due to slow shutter setting used in low light situations (remember rods "legend")
The "swimming", waves in trajectory could be very well again an artifact, a combination of remanence and scaning lines of the image done in camera
electronics, this generating "breakings" especcially in faster movings (camera pan or objects moving fast)
Similar, CMOS senzor used in many video or photocameras does suffer from artifacts because of the way they scan the image line by line in the
For this effect, someone could learn here:
or find tons of results here:
Of course, i don't know if NASA camera are using something like these CMOS senzors, but sure the NASA cameras have their own WEAKNESSES, and somehow,
an experimented technical user could recognise many of them. I'm not too experimented, yet i recognise some of this. So, i can't think straight and
easy to the "OMG alien there", but more i can understand that i have much to learn in the field on technics before jumping in wild conclusions.
[edit on 26/8/09 by depthoffield]
[edit on 26/8/09 by depthoffield]