Recently in Internet discussions there appears to have been an attempt to resurrect the old NASA claim that there are images in which "the face disappears." This is evidently a result of the publication, in the Web Page issued by the Mars Global Surveyor Principal Investigator, of some of the few very low resolution Viking images which include the Face but are taken from a much greater distance than the well-known Viking frames 35A72 and 70A13. The tack is to claim that these low resolution images, which show little detail at all, are the "disproving" images.
Frames 35A72 and 70A13 were taken from a distance of about a thousand miles and have a resolution of 47 and 43 meters (smallest resolved object about 147 feet across). Most of the other images that include the Face were taken at a much greater distance and have very low resolutions (700-800 meters). They are essentially useless for studying the "Face" or any of the other objects of concern at Cydonia.
However, there are four images with somewhat better, though still quite low, resolution: Frame 561A25 (163 meters = 535 feet, afternoon sun), frames 673B54/56 (226 meters = 741 feet, afternoon sun), and frames 753A33/34 (233 meters = 764 feet, morning sun).
To get an idea of the difference in resolution between these frames and the two higher resolution frames, note that since the face is about 2,000 meters wide and 2500 meters long, in the higher resolution frames the Face image provides about 2,000 pixels of information; in the best of the lower resolution frames we have only about 15 pixels; and in the remaining two merely 8 or 9 pixels. One cannot, therefore, expect much information from these low resolution frames.
The low resolution frames were identified by the independent investigators quite early on, after several searches through NASA archives. In Unusual Mars Surface Features by DiPietro & Molenaar (1982, 1988) frames 673B54/56 and 753A33/34 are listed along with photographic reproductions of all four. In anthropologist Randolfo Pozos' account of the first independent Mars investigation, The Face on Mars (1986) a dramatic account of the search for additional frames by the independent researchers is given. A good enlargement of frame 753A33 appears on page 54 of Pozos' book. That image, although lacking in detail due to the low resolution, clearly shows the underlying symmetry of the structure.
On page 37 of Dr. Carlotto's The Martian Enigmas (1990) a high-quality enhancement of the Face from frame 753A34 is shown alongside a computer-generated image (derived from frame 70A13) which duplicates the same morning sun angle as that of 753A34. Dr. Carlotto's enhancement algorithm brings out enough large-scale detail in 753A34 to reveal the morning sun illuminating the major features such as both "eye sockets" and the "mouth." It also corroborates the overall symmetry of the mesa. But because of the poor resolution little else can be determined.
The best of the low resolution frames is 561A25. The Face in this frame clearly shows the overall symmetry and basic facial features, but with much less definition. The afternoon sun angle is about the same as that in frame 70A13. The image, reproduced here, may be compared with Dr. Carlotto's enhancement of 70A13 to see the overall structural similarity.
As for the others at yet lower resolution, even if the facial features are not clearly evident this proves little, given the resolution. The critic who takes this tack is arguing in effect: " the facial features are too visible in the high-resolution frames, so let's find frames with resolution so low you can't make out the face, then use these to prove the face disappears." But this is clearly a move of desperation. To argue that these low-resolution images should be given precedence over the sharper, higher-resolution frames 35A72 and 70A13 is to take the scientific process backward.
Actually it is unlikely that the NASA scientists ever had any images in mind when this allegation surfaced. Upon the discovery of the Face in July 1976, a Viking Project Scientist held up frame 35A72, containing the Face, and announced to the assembled press corps that in a picture taken "a few hours later" it all "went away." (see Report, page 11). But he did not show this other picture. Actually there were no frames taken a few hours later: The spacecraft, with an orbital period of about 24 hours, would not return to the site for many orbits to come. (Frame 561A25, for example, was taken by the "A" orbiter on its 561st orbit -- 526 orbits later.)
Thus the rumor that there was an image in which the Face "disappears" began with reference to a nonexistent frame.It seems likely that NASA simply picked up on this original misstatement and carried it along as "fact" for almost two decades without checking on it. In August 1993 I asked Mr. Donald Savage of NASA's Public Information Office to discover, if possible, what Viking frames the NASA scientists had been talking about. After a two-week search, Mr. Savage reported back to me that "Nobody here [at NASA] knows."
In 1985 Dr. Carl Sagan attempted to produce a "disconfirming" image in a Parade Magazine article "The Man in the Moon." The best he could come up with was a poorly processed version of frame 70A13, which had been colorized so as to diminish the clarity of the facial features. Had there been knowledge of images in which the Face genuinely "disappeared" he surely would have used these instead (for a full account see Report, Chapter Eight).
In its current statement on the Face, which still maintains the "trick of lighting" argument, JPL significantly does not mention the existence of any frames in which the face allegedly "disappears." Instead, the JPL statement says "if the image had been taken at a different time of day...then the rock outcrop would probably have had no resemblance to a face" [editor's italics]. So NASA itself has moved from stating that there are "images in which the face disappears" to saying that if such images had been taken, they would "probably" not have shown a face. This is certainly unscientific support for the "trick of lighting" theory.
There is, however, a more important factor to be considered here. As pointed out in The McDaniel Report (pages 38-39), the fact that under certain lighting conditions the features of a sculptured face may not readily be discerned does not prove that the object does not have the shape of a face. The basic argument -- that if an image is found in which the facial features are not easily discernible because of the lighting then such an object has been "proven" not to have those features -- is simply fallacious. What would prove that the features are a trick of lighting would be to specify what objects, not shaped like a face, are throwing the illusory shadows. NASA has been unable to do this.
