MARTIAN SAND LIFE: EVIDENCE AND PREDICTIONS
By Francisco J Oyarzun
These days of June 2004, I see no less than four lines of evidence to indicate that some life remains today on Mars, associated with sand. To wit:
Line 1. The Dark Dune Spots studied by Gánti, Horváth, et al.[1]: seasonal spots that form only on sand dunes, between about 60ºS and 82ºS, never crossing the edge of a dune. If they are truly biological, then there is a simple explanation: the organisms hide in the porous (and easily traversable) sand when conditions are bad, and come to the surface only when conditions are right (sun shines round-the-clock and melts a thin layer of water under the ice).
Line 2. "Organic" shapes in closeups of sand taken by NASA's Mars Exploration Rovers (MER). They include, on top of sand banks such as "Serpent", the unexpected monolayer of pebbles(?) for which a physical explanation is wanting, and which include some remarkably complex shapes, plus, within the sand itself, apparently segmented filaments and other "organic" shapes that I pointed out in my previous essay for Marsbugs [2]. Figure 1 shows another example (Meridiani, Sol 89):
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Figure 1. Sand "rose"; left is unretouched, right has 35% normal edge sharpening. From
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We see a fiber, about two pixels wide (~60 microns), leading up to a pair of diverging curls enveloping some smaller structures; the fiber itself appears kinked and with knobs, as if the knobs were buds, and the curls and their content appear finely segmented. Granted: the overall unity could be an illusion; the knobs could be grains of sand (even though, in the sharpest image, they do not give that impression), but we undeniably have that fiber (among at least four kinds of fiber other than manmade ones: see my previous report [2]), and, coincidentally, we have yet another example of a radially-symmetric fuzz of gossamer fibers, at 11 o'clock from center. I invite the reader to verify, that close inspection of most well-focused pictures of freshly disturbed sand, from Gusev as well as Meridiani, reveals non-random patterns like those in Figure 2: bilateral symmetry, radial symmetry, filaments, branching, repetition/segmentation, at a level of complexity that we normally associate with living organisms.
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Figure 2. Organic shapes from "Serpent" sand bank (Spirit Sol 73), 35% normal edge sharpened; right, tinted. From
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Critics have pointed to pseudofossils, tufa, helictites, and various speleothems on Earth as examples of organic-looking inorganic structures. I have yet to see such an example, however, that was not formed in a water-rich environment, and I have yet to be shown a strictly inorganic fiber that was sticky, as the "cobwebs" in my previous report appear to be.
Line 3. Sand "snakes" in reticulate patterns, that often stop dead at a small stone, as illustrated in Figure 3, which contrasts the "snakes" with a normal-looking sand wave right next to them (also, there are some suspect filaments around the "cock's head", bottom left). Wind alone cannot form such nitid "snakes" unless they have somehow been reinforced. If the reinforcing agent is biological, then the underside of stop-stones could be a "home base": I would expect the "snake's" hypothetical content to angle downwards at the stone. Such a conjecture could be resolved by the Spirit team if they decided to address the issue: a disturbance to a sand "snake", and closeup photograph thereof, might reveal an abundance of filaments, or something more surprising. (As of this writing, it appears that not enough team members are yet willing to question last year's "dead Mars" paradigm.)
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Figure 3. Sand "snakes"; unretouched, from |
While other evidence accumulates, let me point out that burying oneself in a raised, wind-exposed, gallery of sand (that shields against UV but is permeable to gases) makes perfectly good sense for a non-photosynthetic organism that is able to exploit the simultaneous presence of carbon monoxide and oxygen in the atmosphere (800ppm and 1300ppm respectively). The perennial question of water may also be answered by sand: every time ambient humidity exceeds 100%, the result upon smooth rock is frost; between salty grains of sand, however, the result could be water-hogging brine.
Line 4. Within a minority of craters, depressions and canyons, at mid-latitudes: dark areas, olive-green to deep emerald green when imaged in color. As I illustrate in Figure 9 below, such dark areas vary in intensity over Martian seasons, and, over longer periods, can vary considerably in extent (Fig. 11, 12). Example of emerald green:
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Figure 4. Reull Valles, 41ºS, by ESA Mars Express, 15 January 2004. From
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Regardless of what one might initially surmise to cause the green coloration, the big question is: what keeps it green? The pervasive Martian dust should have covered it long ago, as we clearly see happening in Figure 5, this year; not eons ago:
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Figure 5. Albor Tholus, 19.3ºN, by ESA Mars Express, 19 January 2004. From
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From Greenish Dune Streaks to the "Ultreya Abyss"
Figure 6
Figure 6 shows MOC photographs of two craters with dark interiors, "cousins" of Bonneville (within the much larger Gusev). If the darkness were simply the result of wind removing some of the
lighter-colored dust,
Figure 7. Source:
one should expect the raised parts of the little
double crater to be darker than the more hidden parts, yet one observes
the opposite. Figure 7 shows the result of dust devils having sucked up some dust from a crater, and we see that the visual effect is quite different.
Figure 8, below, shows the haunts of the Spirit rover (at 10m per
pixel in the 72dpi original): Bonneville is the lower of the three dark craters.
What determines that so many similar craters on that picture are
light-toned inside? Are the physical conditions really that different?
Or are they just different enough to allow or not allow some dark and
highly stressed life form to take hold?
http://www.msss.com/mars_images/moc/2003/12/02/
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Figure 8. Bonneville environs, from
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I don't have an exact date for Figure 8, but its tone and
contrast correspond approximately to the lower member of the next pair,
taken in July of 2003. The upper member, from a month
before Spirit's landing, has much less contrast, and said contrast is
consistent with high-resolution images taken in January 2004,
shortly after landing
(example:
http://www.msss.com/mars_images/moc/2004/01/23/).
| Also, we can see that many a dust-devil track, visible in July, come December has been obliterated. Spirit press releases have commented that atmospheric dust diminished between January and March, 2004; certainly there have been no dust storms between landing and early June. I surmise then, that the "December" half best represents the amount of fine dust cover in Gusev, when Spirit reached the rim of Bonneville and took the panorama of Sol 68 (March 12), a piece of which I show next, in Figure 10. |
| http://www.msss.com/mars_images/moc/2004/01/05/2004.01.05.R071606.R121091.medium.jpg | |
The color-rendered Bonneville panorama is widely disseminated, in various sizes and "enhancements"; for Figure 10 I've used a 9.2MB NASA original which, apparently, has been superseded by a version almost thrice as large but inferior in sharpness as well as color. From top to bottom, the clip shows (a) the stony lower edge of the crater rim; (b) dunes that look naturally wind-combed but are almost uniformly greenish-dark; (c) dust-colored sand with short sharp greenish streaks; (d) the hard floor, dust-colored with no streaks.
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Prediction 1: to the extent that the changes in contrast (detected via satellite) are cyclical, one should expect in coming months that the greenish dunes get darker, and the streaks grow more pronounced.
To test this prediction, we shall have to wait for the ESA Mars Express satellite to do its best; but Prediction 2 (farther down) should be resolved by the end of July 2004.
Contrast Figure 10 with the streaky crater I showed in black-and-white (Figure 6): I find it unbelievable that dust devils can draw such sharp and narrow streaks (confined to the sand banks!), as for instance the snaky one, lower right (and yes, Bonneville does host a few "sand snakes" as well). I thus boldly present hypothesis A:
1. Some sandy depressions on Mars harbor a photosynthetic life form, that lives in the sand, and is able to push through the clay-colored dust that periodically covers it.
2. Said photosynthetic life form is what makes some craters and other depressions dark.
(Greenish pigments notwithstanding, I do not mean to imply oxygenic photosynthesis; in fact, the presence of carbon monoxide in the Martian atmosphere makes it thermodynamically favorable to fix CO and release CO2)
As an example of multi-year change, I offer the so-called "Big"
crater near the Pathfinder landing site, imaged by the Viking I Orbiter in
June of 1976, and by the MOC in April 1998. Links and captions for both are at
http://www.msss.com/mars_images/moc/4_25_98_pathfinder_release/.
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North is up in both cases. The Viking image (Figure 11) clearly shows, inside the "Big" crater, a macula much darker than a shadow, that takes up about one-sixth of the area of the crater. Twenty-two years later, said macula is reduced to a few spots:
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This change has nothing to do with "defrosting patterns" (as Dr. Malin has called the seasonal Dark Dune Spots), nor with dust devils, nor with dark slope streaks that happen suddenly. They are slow changes that happen, at mid-latitudes, in a minority of craters and other depressions. In the "other depressions" category, I greatly look forward to the "Inner Basin" of Columbia Hills (don't we all?), shown here in perspective:
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Figure 13. Source:
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To give an idea how dark that Inner Basin is, Figure 14 shows an MOC closeup, rotated so that North is up. (Colorized, but the MOC lacks a filter for green.) There are ongoing forum discussions (for example, at http://www.markcarey.com/mars/forum.html) that are assuming that the darkness is a deep shadow, and are calling the largest dark feature the "Ultreya Abyss" on the assumption that it is very deep, possibly a cave entrance.
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Let us congratulate the Spirit team for leading the rover in that
direction! If that succeeds, then sometime in July, I may get egg on my
face by proclaiming, now,
Prediction 2:
Ultreya is not an abyss, but a
depression that harbors a high concentration of dark photosynthesizing
organisms.
References and Endnotes
The html version of the document you are reading is at
http://homepage.mac.com/ttelos/BioMars/OrganisMER/sandLife.html
The author would like to be contacted at francisco-o@earthlink.net
[1] "Dark Dune Spots"
Gánti, T., A. Horváth, S. Bérczi, A. Gesztesi, E. Szathmáry,
Dark Dune Spots: Possible Biomarkers on Mars?
Origins of Life and Evolution of the Biosphere 33, 515-577.
The online Astrobiology Magazine has run several articles on the
subject, e.g.
http://www.astrobio.net/news/modules.php?op=modload&name=News&file=article&sid=738
[2] "Organic" shapes were reported on
by F.J. Oyarzun in Marsbugs 11, numbers 17 and 17
(April 2004); said report can be accessed in English and in Spanish,
from the bottom of this page:
http://homepage.mac.com/ttelos/BioMars/OrganisMER/
