What are the 'Blueberries" - What are the spheres Opportunity found?

REB · 2004-04-28 14:32:31

I have been studying Geology for a couple of decades now, and I am at a loss for an explanation. Leave to Mars to come up with something new.

The one explanation that I keep pushing away, but it keeps creeping up the back of my mind, is that (let me make sure no one is looking and whisper it to you) is that they have a biological origin. The skeptic in me says that there has to be a Geological explanation, but the things are evenly distributed in the parent rock, they are of a different composition from the parent rock, they are spherical and roughly all the same size, and they are found in a fossilized shoreline environment.
The even distribution of the spheres and being the same size just seem odd for a geologic explanation. There might be one, but I don’t have it. Mars has surprised me more than once. I am sure I will be surprised again.

The fact that they are all around the same size is really the kicker. Tektites would vary in size. So would sphere formed by other geological process. Why are these roughly all the same size? True, in some rocks, like granite, crystals will be of similar size because of the cooling rate and the amount of minerals in the solution, but it is nothing like this.

I just don’t know. I keep coming back to life. You can go to the beach and find seashells of the same species that are similar in size.

The problem I have with the spheres being formed from life, is that they are evenly distributed. Like with tektites, I would expect sphere, formed from life, would be in certain layers, unless they formed after the sediments were deposited. I would love to see a well cut cross-section of the layers.
Could some ancient mars life have tunneled into the layers during the last time the area was flooded?

At this point, I am not ruling out anything. Mars has fooled me before. I’ll wait for more evidence.

ERRORIST · 2004-04-28 16:35:46

Here is what they are. Any thoughts?

http://www.divediscover.whoi.edu/vent_c … ...s1.html

GraemeSkinner · 2004-04-28 23:42:39

Here is what they are. Any thoughts?
http://www.divediscover.whoi.edu/vent_c … ...s1.html

Well the fact that the size of the ones in the image are somewhat different from the ones seen on Mars, just because the spherules look like something on Earth does not make them automatically the same thing - but hey this is Mars we're talking about so anything could happen/be true.

Graeme

Mark Friedenbach · 2004-04-29 00:18:02

hematite via precipitation:

http://www.cnn.com/2004/TECH/space/03/1 … ies/]click

REB · 2004-04-29 07:39:54

They are made of hematite, but how they formed is still under question. I feel more ‘comfortable’ with a geological process, more than a biological process, but I have yet to see a good geological process.

If they were formed via precipitation, then why don’t they have a banded structure, and why don’t they differ in sizes? They seem to have a size limit. And what is with the ‘stems’? Are they a product of weathering, or something else?

So many questions.

So I am still puzzled that all the spheres are the same size. A biological explanation seems to work better than a geological one- but this is Mars.

Even more puzzling is the even distribution of the spheres throughout the rocks

When we look at the layering in the rocks, the bottom layers were deposited first from the ancient sea (assuming they were deposited in a seabed) So we have ‘blueberries in the older layers.

If we move up the rock layers, the deposits get younger, yet we have sphere in those layers as well. This means that sphere are being evenly deposited (Or formed on the seafloor) in each time period, and the ones on the bottom are older than the ones on top (And if life did create them, then they have not evolved).

Or the spheres are all the same age and they formed after the layers were deposited.

C M Edwards · 2004-04-29 08:37:23

I’ve done a preliminary analysis of some of the soil sample micrographs, looking at size distribution patterns in the hematite blueberries at Eagle crater. The following mosaic is a good example of some soil micro-photos by the Opportunity rover:

http://marsrovers.jpl.nasa.gov/gallery. … ..._br.jpg

and this non-micrograph picture of the “Berry Bowl” site was interesting as well:

http://marsrovers.jpl.nasa.gov/gallery. … ..._br.jpg

It’s been noted that the size distribution of these hematite concretions is not uniform or balanced. There appears at first glance to be a distinct upper and lower limit to their size throughout the Eagle Crater site, with the average size of the globules being closer to the upper limit than the middle of the range.

I find that there is indeed an upper limit to the size of the hematite blueberries, which is on the order of about 3mm but actually varies significantly from sample to sample. The largest blueberries exceed 5mm but those are quite rare. The average is between 2.5mm and 3mm, despite the fact that the typical median value for soil samples is usually closer to 1.5mm.

There is an observable lower limit in several of the samples, but not all. Further, this lower limit is not consistent from sample to sample. I attribute this to two effects: 1) resolution limits and other artifacts in the images which make my sampling techniques unable to discern the smallest particles, and 2) size separation of particles due to saltation in the soil samples.

This link is an article discussing size separation of particles in a collection of vibrated granules:

http://jfi.uchicago.edu/~jaeger....ure. … ...ure.pdf

Windblown granules can be expected to behave similarly as they are deposited during saltation, though over longer time periods.

The graph at the beginning of the article indicates what would be necessary for large particles (like the hematite blueberries) to separate vertically relative to the surrounding grains as the soil is blown along the surface. This data suggests that the largest blueberries would rise to the top of a vertical column of windblown grains over time as they were carried along, with the smaller blueberries remaining buried, thus segregating them according to size and concentrating the larger blueberries on top. It also suggests that the particle separation will be influenced by relative density.

How large this difference in density is may provide an additional clue to the composition of the little spheres. For example, if they are porous (and thus less dense), their distribution will vary slightly from that of solid hematite granules.

The separation of sizes during saltation should leave the largest particles on top. The size distribution is fairly sharply limited to 5mm. This suggests that something prevented the growth of hematite blueberries larger than 5mm. However, particles in the surrounding (possibly non-hematite) grains which are of sufficient density to separate at the same rate as larger, less dense particles will mix in evenly with those particles, concealing the smaller hematite particles amid the rest of the dust. This accounts for the observed lower size limit and its variability from sample to sample.

Given the assumption that relative separation periods for windblown separation are proportional to those for vibratory separation, it is possible to set limits on the density range of the hematite granules in these soil samples.

Assumptions about the surrounding grains are necessary for exact density figures, but not for estimating relative density. For example, the average density of solid hematite is 5.3 g/cc, while the average granular density of silica sand is 2.6 g/cc. Solid hematite grains are twice as dense as solid silica sand grains. So, according to the results in the attached article, the smallest grains of solid hematite we should see always on top of a windblown mix of silica sand and hematite are those whose size is at least 25 times that of the average sand grain. Anything smaller than that would be mixed in evenly with the rest.

If the surrounding granules were 10 times denser than the hematite blueberries, the smallest blueberries would be less than 5 times the average diameter of the surrounding grains. Similarly, if the surrounding granules were also largely solid hematite (yielding a density ratio of 1), the smallest observed diameter should be at least 15 times the average diameter of the surrounding grains.

The smaller the smallest hematite grains are, the lower their relative density is.

My estimate is that the smallest granules are about 10 to 15 times the size of the smallest grains, but this is likely inaccurate due to limits of image resolution (the smallest grains are likely smaller than my estimate, making the actual size ratio higher). This suggests that the hematite blueberries are not significantly heavier than the smaller particles that comprise the rest of the windblown grains. This finding is consistent with large, solid hematite granules atop a sand composed largely of hematite. It would also be consistent with large, porous hematite granules atop a sand composed of lighter particles, such as silica grains. However, the lower size limit observed does not support a density ratio less than 0.7 or greater than 1.3.

In short, the hematite blueberries are about as dense as the surrounding dust.

Thanks for your time.

CME

REB · 2004-04-29 08:48:10

Interesting. They are not very dense (Make sense, since they lie on top of the sand and dust), but they are harder than the parent rock they are in (They don’t weather as quickly). Reminds me of bone, or coral.

cassioli · 2004-04-29 08:49:46

I?ve done a preliminary analysis of some of the soil sample micrographs, looking at size distribution patterns in the hematite blueberries at Eagle crater. The following mosaic is a good example of some soil micro-photos by the Opportunity rover:
http://marsrovers.jpl.nasa.gov/gallery. … ..._br.jpg
and this non-micrograph picture of the ?Berry Bowl? site was interesting as well:
http://marsrovers.jpl.nasa.gov/gallery. … ..._br.jpg

Your links have been cut and are not working.

Luca

atomoid · 2004-04-29 13:42:14

...Even more puzzling is the even distribution of the spheres throughout the rocks
When we look at the layering in the rocks, the bottom layers were deposited first from the ancient sea (assuming they were deposited in a seabed) So we have ‘blueberries in the older layers.
If we move up the rock layers, the deposits get younger, yet we have sphere in those layers as well. This means that sphere are being evenly deposited (Or formed on the seafloor) in each time period, and the ones on the bottom are older than the ones on top (And if life did create them, then they have not evolved).
Or the spheres are all the same age and they formed after the layers were deposited.

Its possible that the layers formed very quickly, geologically speaking, layers deposited in faily quick succession, and that a large vertical column of layers remianed saturated until it dired up on a very quick timescale. When a uniformly saturated bed dries the minerals will precipitate out and these conditions should produce similar results throughout the vertical column.

Or i might be somewhat malinformed, the hematite blueberries necessarily need a long timscale to develop in? and therefore there shoudl be a greater size variant between them? im going on the assumption that they are the result of mineral concentration via evaporation rather than slow accretion (but im not a gelogist!) i guess im making the rash assumption that Mars atmosphere was close to vacuum before these layers were deposited and when these layers were created the water boiled off over a couple thousand years alowwing this concentration to take place on a short timescale. My other rash assumption is that the bedrock is very silty has very little "glue" holding it together (didnt get much time to develop a complex soil chemistry during the deposition event) so it breaks up readily and erodes very quickly into fine dust that gets almost completely removed from the area leaving a pavement of blueberries protecting the soils beneath from further erosion. please correct me if you see it otherwise as i have a low level of confidence in my above assumptions.

C M Edwards · 2004-04-30 12:26:36

Hmm… I lost two of my examples. However, all they were was a collection of representative soil target micrographs and a picture of the “Berrybowl” site in Eagle crater. I am confident that analysis of any similar set of micrographs from the area would yield the same basic conclusions.

In light of the data that the subsoils in the area are mostly hematite poor basalt grains, I am reaching an interesting conclusion regarding the blueberries based on my hypothesis that sorting during saltation accounts for the observed size distribution.

I believe that the blueberries in Eagle Crater are composed primarily (>50%) of a mineral other than hematite (iron oxide) which is less dense than goethite (iron hydroxide), one of the lightest iron-bearing minerals. If my own analysis of their density is correct (admittedly a big if), hematite is not the primary component of the blueberries in Eagle Crater. They could not be solid hematite, or even mostly hematite.

The culprit mineral could be an alkali salt, a carbonate, or something else that doesn’t show up well on the spectrometers. Or the grains could be porous. But they would definitely not be pure, solid hematite.

REB · 2004-04-30 14:18:33

This is very interesting. They appear to have a low density but a high hardness(In relation to the parent rock). I can’t think of any low density mineral on the Earth that has a low density but a high hardness. Limestone has a low density and what I would call a mid range harness. The strongest, low density mineral made objects I can think of are made of Calcium- bone, shells and coral- all made by life.

I wonder what the actual hardness of the spheres are? And are they really less dense than the parent rock, or do they somehow resist weathering better than the parent rock that is not based on their density? (Like chemical weathering). The parent rock could have a hardness of 1 or 2, while the spheres only have a hardness of 4 or 5.

The parent rock does not seem to last long while exposed to the Martian air. It dissolves quickly leaving the blueberries. Normally, rocks would be thrown all over the area like from the impactor that created Endurance, but yet we see no rocks scattered around. The only rocks we see around this area is where bed rock is exposed and where other rocks have been thrown there from impacters outside of the region.

chaosman · 2004-05-01 14:00:01

Also interesting: Berry close up analysis by someone...

http://www.xenotechresearch.com/marsind … rsindx.htm

cassioli · 2004-05-05 12:04:12

These damned bluberries are so meddlesome and omnipresent that I am beginning to think it could be a damned seaweed or some kind of vegetable parasite! They are completely invading even the Endurance crater: my RGB composition of pancam images gives out a completely blue Endurance! (I'll not post it, it's really TOO blue to be realistic...)

I am beginning to see damned blueberries even in my nightmares!

Blueberries, blueberries, blueberries everywhere..... :realllymad: ???

Luca

cassioli · 2004-05-05 12:10:54

Ok, I post my images... but take them with care:

http://jumpjack.altervista.org/immagini … e.jpg]Blue endurance - 1

http://jumpjack.altervista.org/immagini … 2.jpg]Blue endurance - 2

I didn't do anything difference from what I usually do: just took L2-L5-L7 and joined them into RGB channels.

:hm:

Luca

REB · 2004-05-05 13:08:36

Cassioli, is that a baby sandworm at the bottom of this picture;

http://jumpjack.altervista.org/immagini … rance2.jpg

The spice must flow!

ERRORIST · 2004-05-05 19:54:59

Just what I thought ice water sand mixture.

cassioli · 2004-05-07 10:56:41

I already posted this image somewhere, but I don't remember where...

I suggested that blueberries could be originated into some craters, and spread around by the wind, as it perhaps appears in this picture. It was just an hypothesis, but now:
- We found a crater with a very dark interior, probably blue
- There is plenty of... "something" in the bottom part of the crater, and it also appears to be blue

Maybe the material at the bottom of the crater is ice, or sand... but if they where thousands of blueberries, "waiting" to be spread around by the wind??? :band:

But, don't ask me WHY they are there and WHAT they are...

Luca

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#1 2004-04-28 14:32:31

Re: What are the 'Blueberries" - What are the spheres Opportunity found?

#2 2004-04-28 16:35:46

Re: What are the 'Blueberries" - What are the spheres Opportunity found?

#3 2004-04-28 23:42:39

Re: What are the 'Blueberries" - What are the spheres Opportunity found?

#4 2004-04-29 00:18:02

Re: What are the 'Blueberries" - What are the spheres Opportunity found?

#5 2004-04-29 07:39:54

Re: What are the 'Blueberries" - What are the spheres Opportunity found?

#6 2004-04-29 08:37:23

Re: What are the 'Blueberries" - What are the spheres Opportunity found?

#7 2004-04-29 08:48:10

Re: What are the 'Blueberries" - What are the spheres Opportunity found?

#8 2004-04-29 08:49:46

Re: What are the 'Blueberries" - What are the spheres Opportunity found?

#9 2004-04-29 13:42:14

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#10 2004-04-30 12:26:36

Re: What are the 'Blueberries" - What are the spheres Opportunity found?

#11 2004-04-30 14:18:33

Re: What are the 'Blueberries" - What are the spheres Opportunity found?

#12 2004-05-01 14:00:01

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#13 2004-05-05 12:04:12

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#16 2004-05-05 19:54:59

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