OK, firstly, if the Mods think this should be in IMHO, then all well and good, after all nobody has been to mars to be able to give me a definitive answer, however…
I’m looking for a rational explanation (not just a bunch of wild-assed speculation about pyramids and faces) of the features in This picture from the Mars Global Surveyor.
The features appear to be raised, as they are casting shadows.
They display the sort of radial branched patterning that is found in plants and corals on Earth.
BUT…
The scale of the image is something like 2.3Km wide, so the largest of the features is probably 800-900 metres across, althoug it’s daft to compare this to the size of living organisms on Earth anyway.
My best guesses so far (aside from the way-out trees/giant lichens stuff) are:
-They are the remains of impact craters, the shadow is cast by the raised rim and the radial pattern are caused by erosion from rivulets (of water?) running toward the centre.
-They are the remains of lava domes that have been eroded (again by water?) into pinnacles similar tothese.
I’m not really satisfied with either of the above, but I feel sure that NASA would be telling the world if they thought that these were organisms.
My guess? Rocks. I zoomed in on the picture, and it looks as if the edges of the “tree” shapes blend into the surrounding ground. Additionally, the “spiral” lines are too continuous to be trees or bushes.
I should also point out that the bottom half of the image seems to resemble sand dunes.
Actually, possibly the most intruguing feature is that the edges of the features are darker than the centres, this makes the look like they are raised, and this in turn suggests lush new growth, whereas the centre looks like old woody material, however in reality, it probably is just that the edges of the features slope sharply downwards and therefore haven’t gathered as much light-coloured dust as the flatter centres and therefore we’re just seeing more of the underlying dark-coloured rock at the edges.
Another possibility is that they are old lava flows I suppose.
Now, I’m not trying to argue the case that they might be trees; I think it’s most unlikely, but we can’t make direct comparisons with how a tree would or wouldn’t look on Earth.
Having said that we can’t make comparisons, just to be devil’s advocate, please allow me to go right ahead and make the comparison; have a look at this picture.
Yes, I know there’s a huge discrepancy of scale in this comparison, but the pattern in the lichen is an artifact of the way that it grows in response to nutrient availability, there is a superficial resemblance between this and the features of the Mars photo. But I’m not sure what I mean to say by any of that… hmmm
Does anyone know of any (respectable) online resource that might have a commentary on this photo (the mars one in the OP, not the lichen)
Well, Arthur C. Clarke thinks they’re trees, but then again, that’s just one man’s opinion. From that article, I thought it was interesting that he said “Something is actually moving and changing with the seasons that suggests, at least, vegetation.” …is this true? Has more than one image been taken of the exact same region?
Keep in mind that geological formations on Mars take many varied and unusual forms. You can browse MGS images here - just click on a few random areas of Mars and find some narrow-angle images, and you should see all sorts of weird (but clearly non-organic) forms. These “trees” could quite easily be just another geological feature unique to one region on Mars.
Having seen many images from MGS, my SWAG is that they are ice formations. Although this image is new to me, MGS photos have already revealed many wild ice formations in the polar caps of Mars.
It’s the same pattern as the first image. I can see why Clarke thinks what he does about these things - they’re very suggestive of biological processes. With a little imagination, you can see how the organisms would take root in a spot and grow outward, forming dark-edged islands that eventually merge into a single plain. These plains die from the inside out, eventually forming pale husks. The few remaining spores are carried on the Martian winds to new locations.
It is probally some rock outcropping with some veins of minerals visable
It seems like it is ‘sand’ at the top and solid rock at the bottom. The rock at the bottom gets higher to it’s high point then ends back at the sand. This could be the point where the ocean met the land like Acadia National Park.
I dunno, some of those “shadows” look more like wind streaks to me. They point in different directions–is that just because the plain is gently rolling? Am I crazy? Phobos?
If anyone would like more tehcnical information for this image, try:
I’m starting to think that Arthur C. Clarke is really losing it. Duh, yeah Mars changes with the seasons. The wind blows dust around. C0[sub]2[/sub] freezes on the winter pole and sublimes in the spring. Evidence for vegetation? Pretty damn sketchy.
I must add also that the “prove me wrong” attitude of the wackos is really annoying. They make some crazy claim about some formation on Mars and when the mainstream rolls its eyes they say, “Well, you can’t tell me how it formed, so I’m just as likely to be right as you are.” (This is not aimed at my fellow Dopers, but rather at the authors of assorted webpages and bulletin board postings I surfed looking for more information about this image.)
If you enjoyed this thread, you might also like the infamous Martian Tubes
These things are near the poles, right? Could they be deposits of minerals left behind when CO2 ice sublimates? Perhaps water ice that was mixed in with the CO2 ice, or something like that? IMNACryogenic Geologist, but it seems semi-plausible to me. Perhaps some experimentation with ice mixtures would be in order. But that would mean disassembling the tokamak in my bathtub, so it’s probably more trouble than it’s worth…
Mold. Big mold. REALLY super huge mold colonies that have been growing for thousands and thousands of years. Mold that would put the stuff growing on that old rice in my fridge to shame.
My first thought when the image appeared on my screen was that I was looking at a phot negative. Wandering through the related site, I did find (in terms I only barely grasped) that this is an electronically scanned picture to which they have applied various compensating levels of gain and offset in order to produce a recognizable photo.
At this point, I would need some verification that we are actually looking at projections from the surface rather than impressions in the surface.
Even taking the photo “as is,” I would have characterized the “trees” as a series of worn cones (dark in color) projecting through some sort of dust base (gray) with dust collected along the ridge tops of the eroded cones.
After careful analysis of the photo (OK, OK, I just pulled it into GIMP and zoomed in and out a bit):
It appears to me, based on the lay of the shadows (particularly around the smaller forms, but around the larger isolated ones as well) that the photo shows elevated landforms at a time when the sun was near the horizon at the lower right of the image. From this, I would suggest that we’re looking at weathered rock formations not entirely unlike those in the badlands of South Dakota (sorry, I was unable to find a suitable aerial photo of the terrain–I got sick of prairie dog survey pages). In such a formation, under the given lighting conditions, it’s likely that only the higher ridges (converging at the highest points of the formation) would be fully illuminated, producing the bright lines visible in the photo. It’s also possible that the ridges resisted the erosion because of the inclusion of veins of more durable minerals, which might also be more reflective (as k2dave suggested). The fact that the brightness of the light lines seems fairly even across the top of each formation suggests that the tops are fairly flat, with no part casting the rest of the ridges into shadow. My guess would be a grouping of butte-like flat-topped formations with deep erosion gullies lying in shadow.
I could, of course, be entirely wrong. It would hardly be the first time.
Has anyone ever had a kit to “grow a crystal christmas tree”? (cystals are grown on papers shaped like a standing evergreen) The things in the picture look remarkably like the “christmas trees” do when looked down on.
