MARS OUTCROP SOURCE OF TINY SPHERES

JPL ^ | sol 13, opportunity, mars | JPL

[FireTrack]

LOL, what's a "Horta".

Btw, take a look at the image with the red circle on the left above. There appear to be several sphere pieces, possibly the result of a fall to the ledge above.

[Darksheare]

Original series Star Trek, a Horta was a silicon based life form that ate tunnels through stone and had sphere shaped green eggs.
The miners of a colony were breaking the eggs and killing the infant Horta.

The sphere pieces there, some of them appear somewhat concave on the interior as if somewhat hollow, or maybe the fracture is like an 'onion' break.
Onion break being that it fractures and flakes off in layers like an onion.
(In my rock collection somewhere is a sandstone piece that did just that.)

But these spheres just are way too weird.
They're regular, and occur way too often to be anomalous.

[Bernard Marx]

I am thinking lithophysae also. But perfectly rounded?

Pisoliths would be a great discovery but the formation hits this old field-tripper's eye as lithophysae or, to use less technical terms, spherulites or mini-thundereggs. I've rolled tens of thousands of identical-looking little rhyolite balls from tuff and perlite beds from the Idaho-Oregon border to central Oregon.

If that's what they are, it would support my case made on another thread that the outcrops are volcanic ash (tuff). Here's what one authority has to say:

"Ross and Smith (1961) simply define thunder eggs as uncommonly large lithophysae (i.e., hollow gas cavities; Greek derivation = "stone bubble") that develop in a welded tuff (welded tuffs are composed of a "plastic" volcanic ash that becomes indurated, or fused, by the internal heat that is inherent in the erupted rock [Thrush 1968]).

"Thunder eggs are generally defined as nodular structures (Staples [1965] emphasized that they should be considered structures, not "rocks") that are formed within high-silica extrusive volcanic rocks or welded tuffs, with the silica content of the rock ranging from 75 to 80 percent (Dake 1951; Renton 1951; Staples 1965)."

I'm aware of your [doodad's] objection that olivine and quartz (silica) don't occur together. I've searched and can't find any report of olivine at this site although it's mentioned at the Spirit site. Maybe I missed it.

[Dan Evans]

Some of the spheres directly below that big rock appear to have no shadow or shading. That would mean they were broken in half and partially buried with the flat side to the camera.

[doodad]

I've searched and can't find any report of olivine at this site although it's mentioned at the Spirit site.

I may have mixed them up. Probably so. I am more amazed at the uniform size across multiple layers so that the same conditions were met over and over and over. I have never seen any concretion, or infilled vugs that consistent in all my, granted limited, experiences.

[FireTrack]

I've rolled tens of thousands of identical-looking little rhyolite balls from tuff and perlite beds from the Idaho-Oregon border to central Oregon.

By identical, I take it that you also mean in size also?

[Dog]

I have a question....hope it doesn't sound stupid.

How could you have water on Mars but no life.

[FireTrack]

Some of the spheres directly below that big rock appear to have no shadow or shading. That would mean they were broken in half and partially buried with the flat side to the camera.

I'm thinking that where you have spheres falling from above and hitting rock, you have pieces of spheres below the rock. Since the fall isn't that great, to me it indicates that the spheres are somewhat fragile.

[Bernard Marx]

By identical, I take it that you also mean in size also?

It's hard to get a read on the size of the spheres in the Mars image but I'm guessing they're something on the order of virtually microscopic up to around a half-inch in diameter. That would fit with what I've observed. Some outcrops seem to consist only of "tinies." But I've also seen "thunderegg" formations larger than full-sized automobiles. It just depends on the conditions of formation. There's another factor I've been wondering about: the effect of Mars' 38% of Earth gravity on geological formations like this.

[FireTrack]

It's possible to have water without life. However, given our limited knowledge, it's impossible to have life without water. At least life as we know it.

[thoughtomator]

Here's a stereo set of the area . . .

I turned my speakers all the way up, but still can't hear anything. Are you sure I'm logged in?

[doodad]

Water is just a chemical, albeit with unique properties. Life as we know it requires water, but water doesn't require life or indicate it automatically. I'm no biologist so I can't explain it right; I think about the areas under the ocean that are sterile plains.

[mewzilla]

Baby Hortas?

[FireTrack]

By water, I mean water in all it's forms which I think is a given that water exists on Mars at least in some form. Hope that clarifies things. :-)

[quantim]

Maybe if Howard Dean wants to run as a third-party candidate he could be founder of the "Pitholith Party" for those who go through life with rocks in their heads!

[Bernard Marx]

I have never seen any concretion, or infilled vugs that consistent in all my, granted limited, experiences.

If we're talking lithophysae (not amygdules) I have. I can recall prying layers of tuff apart and having loose ones roll out like little ball bearings. Amygdules (infilled vugs) tend to be almond-shaped which is where the name comes from I think (from the Latin amygdala).

Of course my theory may be entirely wrong. But it seems consistent with what we can so far observe from limited data. Maybe other theories do too. Discussion is certainly invited!

[Ichneumon]

This is clearly a case of Martian acne.

[FireTrack]

How fragile are the formations that you have observed? Do they break easily? Do they break into halves or do they shatter?

[doodad]

I'm with you wondering if the Martian gravity had some effect in all this. As I noted earlier, the spheres appear to be in the top of each layer. A gas would certainly behave that way, in fact I have collected samples at Sheepeater's cliff in Yellowstone that each discrete flow of basalt was marked by the froth at the top. I am not sure that lithophysae would be of such a different density that the remainder of the rock. The obsidian flows I have seen were just as hard across the devitrified sections as the remaining rock.