INSIGHT

I sent an email to Jeffery Sainio who is the Staff Photoanalyst for MUFON. The following are his responses and my question. I would also like to thank Jeffery for spending the time in analyzing this NASA image. It is much appreciated!

From : Jeffrey Sainio
Sent : Monday, January 10, 2005
To : Peter Arvo
Subject : Re: Mars Rover Image
Gee,whatever it is, it's guaranteed extraterrestrial... and not a bird, insect, or airplane.

The anomalous streak is not verified by the right camera of the stereo pair, which suggests a check of equipment malfunction is in order. The darkest point of the streak has a greyscale value of 8, while an adjacent pixel is 222, typical sky brightness. I could find no other such contrast (i.e. near-black adjacent to near-white) anywhere in the photo. Such failure to discover such contrast is hardly unexpected,
since focus is never perfect. Borders between known dark and light edges, such as the horizon, or nearby bright rocks, are spread out over 3 or 4 pixels. This extraordinary contrast indicates the image was not created by light passing through the lens, since the lens is incapable of creating such an image. Some other cause is probable. I'm no expert on the electronics of these imagers, and detailed knowledge is needed to know all their oddities. As an example of other defects, note the unfocused test image in the link below, and also the half-dozen specks which cannot be 'real' objects: >
http://marsrovers.jpl.nasa.gov/gallery/all/1/p/318/1P156413415EDN3940P2697L7M1.HTML

From : Peter Arvo
Sent : Monday, January 10, 2005
To : Jeffrey Sainio
Subject : Re: Mars Rover Image
Jeffery,

Thank you very much for your input it is greatly appreciated.

I did talk with several individuals at NASA and JPL and they tell me that their guess is dirt on the lens. They are going to email me a white paper with the technical specifics of the navigation rover cameras, so that I can look into this further.

It's my understanding that you believe that it is most likely a data error while taking the photo, or that the error occurred in transmission. Correct?

Also, is it ok if I publish your comments to the Internet?

Thank you again for your time.

Peter Arvo

From : Jeffrey Sainio
Sent : Tuesday, January 11, 2005
To : Peter Arvo
Subject : Re: Mars Rover Image
Obviously, they know more about their lenses than I do, but...

This explanation begs the question of where the dirt went for the next photo. I suppose it COULD have been blown off by the same wind that put it there. The 'dust' would have to be fibrous, not a pointlike object such as a tiny sand grain. Of course, Opportunity just
visited its busted-up heatshield which may have released such fibers.

Typically, the surface of the lens package is extremely OUT of focus. I'd challenge anybody to focus their camera at a distant object, stick their thumb on the lens, and see a focused thumbprint. In this situation, the anomalous image is extremely IN focus. The theory contradicts the data. There are other locations within a complex lens system which are also focus planes. These locations are typically internal, sealed and inaccessible to dust. I can't be certain
without lens data. I don't believe another focal-plane can exist without an intervening lens, but those guys at NASA might know something I don't.

My best guess is a data error, possibly caused by a physical event such as a cosmic-ray hit(atmosphere isn't very helpful in blocking them) on the imaging CCD or whatnot; most data errors at locations other than the CCD would cause vertical or horizontal defects.

Regarding transmission errors, again I'm no expert on their transmission protocol, but typically there is error checking & correction of each stage of data transfer. A corrupted transmission
would be tossed out, possibly causing the black squares frequently seen in these images.

You are welcome to use my comments elsewhere. I'd appreciate if you'd point out that I'm the Staff Photoanalyst for MUFON, and that my expertise is primarily terrestrial. These rovers are a far cry from the home-electronics systems that I've become familiar with, and there are certainly better experts (somewhere) than I. BUT if you're told this is dirt on the lens, with no explanation of why such dirt would be in perfect focus, you haven't found an expert.

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