This is a very interesting previously published report by Gilbert Levin of Spherix (formerly Biospherics):

http://mars.spherix.com/color/color.htm

Relating to this, I have scanned a letter from my files that I had received from Mr. Levin back in 1983 when he sent me a print copy of the same report linked to above:

http://www3.telus.net/paulanderson/levin_letter83.jpg

Of note is the reference to follow-up studies showing the "yellow-olive-greenish" patches to be about 1 mm in thickness, although no other details were given and I haven't seen any other information about this since then - ?

(Note: my last name used to be Berry, as on the letter, before I changed it to Anderson, my original family name, back in 1992).

As these kinds of features are of particular interest to me, I might also do a short write-up for the new blog when I get a chance. I'm not saying this must be biological, but that it could be, especially given the recent findings of lichen surviving in space and briny water being able to stay liquid on Mars' surface (according to the new simulations).

May I suggest that -- given what we now know about the enormous degree to which sulfur chemistry and surface weathering govern the Martian surface -- Levin may just be looking at yellowish patches of sulfate salts?

Hi Bruce,

That's a possibility, of course, although the spots were distinctly greenish (more so as seen in the six channel data than the 3 channel data) and the saturation levels of the spots were similar to that of lichen on Earth rocks in the test lab. Perhaps other sulfur / weathering-related tests could be done now?

What I'd also like to find out more about is, as outlined in the original report, the changes observed over time of colour and position of the spots, on both rocks and soil. No spots or changes were seen in the trenches dug by Viking 1. Levin covers several theories about all of this, including wind movement, different sun angles, frost, reflection from crystal facets, descent engine exhaust, artifacts of the imaging system, and lastly, biology. And also weathering in the follow-up letter. I'll see if I can find the report referenced about that in the letter.

Regarding the "green" <sort of> patches on rocks reported by Gilb Levin.

Try to dig up my article "Martian Soil Stratigraphy and Rock Coatings observed in Color Enhanced Viking Lander Images". Proceedings of the 10'th Lunar and Planetary Science Conference (1979) p3055-3077.

It should be findable in larger geoscience and/or astronomy libraries.

Gilbert Levin did a half-comprehending quick-and-dirty analysis of colorimetric data from the Viking Landers, focussing on rocks and soil surfaces at the Viking 1 site. I think he may have been the first to try any quantitative analysis of colorimetric data from the landers for scientific purposes. Unfortunately, rather little other work was done by other people, and most of mine was published as extended abstracts, but not in peer-reviewed journals.

Withough re-reading and minutely dissecting his article, linked to at the start of this topic, mostly off the top of my head, here are some comments. Gil observed that there were distinctly different colored surfaces on rocks and to a lesser extent on soils. In particular, he focussed on spots on the rocks which appeared greenish in color renderings and had lower saturation and different hue numbers in a quantitative lightness/hue/saturation analysis of the 3-color image data. Considerable effort is made in the article comparing these features to lichen patches on rocks imaged by lander cameras on Earth in "rock garden" testbeds.
He does this with the continually suggested arguement that while the features and their changes with time could be explained by soil deposited during sampling operations and by wind deposited and eroded dust, but it would be just as reasonable to infer these features are biologic in origin.

Analysis of lander images following the 1997 dust storms showed multiple changes between primary mission images and post storm images. At the end of Lander 1's life, some conical dirt-piles made to test for possible wind erosion were substantually eroded and redistributed, much as dust on Spirit rover was eroded and shifted on the calibration chart and magnets. Levin has continued over the years to ignore this evidence or at least to minimize it.

My LPSC-10 article and subsequent abstracts showed that Levin's "green" patchs on rocks and soils are the dark, relatively blue, low color saturation rock surfaces seen at both Viking sites, Pathfinder, and Gusev. Spectral analysis I published in extended abstracts show these rock surfaces to be darker and have grayer spectra than soils, and have stronger absorbtions in the near infrared than soils and bright rock surfaces, consistent with being relatively unweathered more-or-less-basaltic igneous rock with relatively small amounts of adhering soil or dust. MER data from Gusev confirm this result and reveal distinct spectral differences between various rock types related to their varying igneous minerology.

Other rock surfaces seen at both Viking sites, maybe at Pathfinder, and certainly at Gusev (maybe also Meridiani) have high albedo, higher than any loose soils, and a distinct yellowish color when compared with widespread redder soils, some darker less red soils (probably with less dust and more basaltic sand) I interpreted them at the time as a weathering coating, formed in-situ on the rock, possibly while the rocks were buried or covered by thick layers of dust. At least some of this interpretation has been supported by MER data at Gusev, certainly the materials are coatings on relatively unweathererd rock immediately underneath. In the LPSC article and varous publications later on, including Astronomy Magazine, these coatings show up bright green to yellowgreen in color-enhanced images. These are NOT the same as Gil Levin's green rock surfaces.

Spectral analysis of the bright rock surfaces from the 6-channel Viking data showed their reflectance rises faster from blue to green than does that of red soils, but then the reflectance rises slower from green to far-red, giving these surfaces a higher brightness in the green filter compared with other rocks and soils than a weighted average of red and blue bands gives. Minerologically, this is the spectal behavior of some of the iron oxy-hydroxides like "goethite", which is a main component of "limonite" yellowish and ochre color in many altered igneous rocks on Earth. Infrared data showed these patches to be bright but intermediate in spectral shape between darker less red rock and relatively red soils.

None of the soils or rocks showed anything like the extremely high infrared reflectances of chlorophyll, and the rocks Gil Levin focussed most intently on have reduced infrared reflectances consistent with pyroxene and / or olivine absorbtion at the longer wavelengths.

I'll have to try to find time to dig out some of my slides and other materials and scan thm for posting. I've been frustrated that nobody followed up on my analysis once my PhD program finished me before I finished it, and that issues I raised and lines of research I initiated have largely been neglected. Much of this is finally being done with the wonderful data from the MER rovers, but between Job and Family, I have not had time to dig into the real scientific meat that is being published in the technical journals.

That's quite an impressive analysis, Ed. Very thorough and authoritative. Especially impressive was your interpretation that some rocks possess a surface weathering rind, as this was nicely proved up with the rocks Mazatzal and Adirondack. I suppose there's a bit of politics involved in the peer-reviewed publication process, no?

Ed, you are damn right !
I agree 100% with your sayings !

Besides, I was myself involved with a NASA colleague in studying "Patch Rock" in 1983 (the name given to Dr. Levin's "green" patch rock) to assess its reality or not for NASA. Our conclusions, after a LOT of image calibrations and processings, were :

(i) no chlorophyll ("algae"), but weathering with dust deposition and removal following the dust storms ;

(ii) an understanding of the so called "blue" (or "bluish")-looking rocks on the surface of Mars : they are mainly basalts ;

(iii) an estimation of dust removal at VL1 site after the 4th dust storm : at least 1/2mm... with the beginning of the seiing of a darker underlying layer of soil ;

(iv) a reassessment of the landing site itself : although there are no clear evidences of rocks rounded by water around VL1, the site is standing clearly within the path of several outflow channels that may have left their marks around in weathered rocks (yet to find then)
==> well you find goethite : GREAT work Ed ! Congratulations ! ;

(v) ...and the discovery of VL1 heatshield small impact crater withs its distinct "V" shape (because we also peered through the hi-res VO images having a 6/7-meter resolution/pixel...

My guess is you meant to say 1977.

Your paper is available as a pdf online:

Martian soil stratigraphy and rock coatings observed in color-enhanced Viking Lander images

Thanks for the input everyone. I'll read through your paper, edstrick, and thanks for the link, ElkGroveDan. All the talk recently of the lichen-in-space, briny water, methane, etc. reminded me of that letter from Levin from back in 1983.

I wanted people to see the copy of that letter, as it is still the only reference I know of to the "patches" having any kind of thickness to them and I'd like to find the study(ies) referenced by Levin showing the patches to be about 1 mm in thickness, which I am trying to do now (couldn't find them on the Spherix web site, so can just do a request I guess). Does anybody here happen to know who this was that published those? Your analysis though, edstrick and vikingmars, showed the "patches" to just be the underlying darker "bluish" rock surfaces. I'm not quite sure yet then how this relates to the patches on the soil (not just rocks)? Is it the same bluish basaltic colouring? If this is covered in the paper, sorry, I'll get some time later today to go through it.

One caveat regarding this or any other possible "bio-looking patches" which may be yet found, I'm not sure if an apparent lack of chlorophyll alone though could be said to be proof of non-biology, as there are of course organisms on Earth which do not use photosynthesis, like fungi (and even 3,000 species of plants as indicated in one overview of fungi I just read, which I didn't know before). More primitive organisms like that (if anything more than microbes existed) might even be expected as it were on a planet like Mars?

Notes: 1977, not 1997. I have a tendency for brain-farts, keyboard "lysdexia" and certainly sloppy proofreading as I approach 6 AM.

I checked the PDF file and was appalled how it turned both the color and B&W pics in to black and white posterized c__p. I'll scan and post the figures in the next few days.

Levin kept hyping the greenness of the patches and the similarity to (often but not necessarily greenish) lichens. He has a way with arguement-by-parallels and suggestion-by-analogy that reminds me of Hoaxland's "logic", though it's not nearly as "crankish".

I did enhancements later on on extended mission images, post-77 dust storms. Much of the soil surfaces at the VL1 site seemed to have been uniformly dusted with storm fallout, and many areas of color contrast seemed subdued or lost. In addition, the field of "blue boulders" (hysterically typoed in the original article to "blue bounders") lost most of their contrast with other rocks in the scene, possibly due to dust deposition on the boulders and cobbles, or some dust being stripped from other rocks.

You found the VL1 heatshield? Do tell!

Bob Shaw

I remember that photo being reprinted in Aviation Week. All I can say is that it shows nothing recognizable as an artificial object to the UNTRAINED eye.

Here is the location of VL1 heatshield crater as seen on VO2 pictures (twice). The excavated dark soil has been since covered by wind sediments (it no longer appears in MOC pictures as a dark "V"). Yes, it was published in AWST (Co-discovered with Jim Garvin).

I got off my <anatomical reference deleted> and scanned in the two color plates from the "Martian Soil Stratigraphy and Rock Coatings..." article.

The PDF file somebody posted a link to utterly TRASHED the images, both color and monochrome, turning all into posterized messes.

I'll have to post more of the Viking stuff.. scan in from 35 mm slides mostly

What is that little "object" on the right side of this viking image???
Click to view attachment

The shroud for the surface sampling boom - ejected by the lander after it got there.

Doug