Skeptic Ginger
Nasty Woman
- Joined
- Feb 14, 2005
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1. April 16 and 20, 2007
2. They are Photos from Opportunity's Microscopic Imager, not from Curiosity
I knew I should have looked it up but I had a 50:50 chance.
1. April 16 and 20, 2007
2. They are Photos from Opportunity's Microscopic Imager, not from Curiosity
I'll offer
"A distinctive characteristic of a living organism from dead organism or non-living thing, as specifically distinguished by the capacity to grow, metabolize, respond (to stimuli), adapt, and reproduce. Or at least four out of five."
I don't know. Maybe it's a horses and zebras question. Having heard hoofbeats, you can't rule out zebras without more investigation, but you could assume that it's probably horses.
Also, the fact that a group of scientists with good reputations said they were hematite, and had access to this data when they reached their conclusions, suggests hematite and wind fits all the available data, and should be considered the "horse" explanation.
ETA: One of the things I wonder about is whether there is any evidence that does not fit the "wind and rocks" explanation.
Also, this is course grain sand. Unlike the fine dust on Mars, this does not easilty blow away with the thin Martian atmosphere unable to exert enough force to do so.
IIRC, it is thought the "blueberries" are hematite concretions that formed in shallow surface water.I saw exactly what RBF saw when I first saw the photo, for the record. That bottom sphere has not grown, we are just seeing more of it because the sand covering the top bit has gone. Extrapolate that reduction in the sand cover to the rest of the photo and take into account how windy we know it can be on Mars and it's pretty clear that's what's happened.
I'm still curious about what they are and how they form, but there is no mysterious growth to account for.
ETA: also the sand we're now seeing seems to be a lighter colour than the (somewhat courser?) sand that previously covered it. My guess is that the second photo is how it usually looks, the first is the exception.
Well, those are good questions. I'm not really equipped to answer them, but I do know that there are, in fact, dust devils on Mars, which means that the Martian wind is powerful enough to lift sand into the Martian atmosphere.That doesn't mean dismissal out of hand is a good approach.
They could be hematite. The colours as described by Devil's Advocate certainly fits the description. However, I am not yet satisfied with the "wind blowing the sand away" claim because there are problems with that theory.
If the wind blew the sand away it and left the hematite spherules behind...
1. Wouldn't the reverse also be true. Would some of the spherules not also have been covered and disappeared or appeared to grow smaller? Was that observed?
2. Why would the wind be strong enough to blow away sand but not blow away, or even move the smaller spheres.
3. This has to be a process which has been going on for a long time, perhaps millions of years. Where are all the previously exposed spherules. Some of these spherules were up to 8mm across, exposed from barely visible to full views in four days. That is a lot of sand that has been shifted so there ought to be piles of exposed spherules on top of each other.
4. The Martian wind is weak, very, very weak. Surface winds are typically 15 to 30 km/h, but with Mars' thin atmosphere (only 1% that of the Earth) the force exerted by the wind is miniscule, about 1/60th of the force of the same wind speed on Earth. The formula is q=½pv2 where
q = dynamic pressure,
p = atmospheric density
v = wind velocity)
A wind of 30 km/h on Mars would exert about the same force as a 4 km/h wind on the earth. Even accounting for the lower gravity, is that enough to move the gritty Martian sand (not dust) around. Note that it takes winds of 100-150km/h to whip up those dust devils, and 200 to 500km/h for a Martian dust storm.
5. Individual dust particles on Mars are very small and slightly electrostatic, so they stick to each other, and to the surfaces they come into contact with. Why do the hematite spherules not appear to have dust and grit partlcles sticking to them?
Difficult to say. Opportunity was not equipped with a wind speed detector.
1. Wouldn't the reverse also be true. Would some of the spherules not also have been covered and disappeared or appeared to grow smaller? Was that observed?
2. Why would the wind be strong enough to blow away sand but not blow away, or even move the smaller spheres.
3. This has to be a process which has been going on for a long time, perhaps millions of years. Where are all the previously exposed spherules. Some of these spherules were up to 8mm across, exposed from barely visible to full views in four days. That is a lot of sand that has been shifted so there ought to be piles of exposed spherules on top of each other.
4. The Martian wind is weak, very, very weak. Surface winds are typically 15 to 30 km/h, but with Mars' thin atmosphere (only 1% that of the Earth) the force exerted by the wind is miniscule, about 1/60th of the force of the same wind speed on Earth. The formula is q=½pv2 where
q = dynamic pressure,
p = atmospheric density
v = wind velocity)
A wind of 30 km/h on Mars would exert about the same force as a 4 km/h wind on the earth. Even accounting for the lower gravity, is that enough to move the gritty Martian sand (not dust) around. Note that it takes winds of 100-150km/h to whip up those dust devils, and 200 to 500km/h for a Martian dust storm.
5. Individual dust particles on Mars are very small and slightly electrostatic, so they stick to each other, and to the surfaces they come into contact with. Why do the hematite spherules not appear to have dust and grit partlcles sticking to them?
Well, those are good questions. I'm not really equipped to answer them, but I do know that there are, in fact, dust devils on Mars, which means that the Martian wind is powerful enough to lift sand into the Martian atmosphere.
And I also know that hematite spherules are heavier than sand, so it could make sense that wind powerful enough to move sand wouldn't be powerful enough to move small hematite spherules, so it seems that there is nothing glaringly obvious about why the wind and rocks theory wouldn't hold up.
So, I think it's worth asking the questions, but the fact that NASA isn't buzzing with excitement leads me to believe that the answers are kind of boring. Hopefully not everyone who is qualified to address the issues is ignoring them, but I am leaning toward the belief that they have, in fact, considered the possibilities, and small hematite nodules and drifting sand is in fact a pretty good, although not very exciting, explanation.
Maybe. I don't know what the surrounding area looked like. There might have been rocks or things where the sand could blow away from that spot but not into it. Keep in mind that this is only a couple inches square.
Due to the thin atmosphere it takes quite a bit of wind to even move these fine particles of sand. The hematite spherules are basically iron, which means they would be rather heavy compared to the smaller lighter sand grains.
They are all over the place at this particular location. Millions of them. They don't pile on top of each other because they are like a bunch of BBs, they are round and just roll down and spread out.
Winds like that can exist on Mars. It is also possible that the rover did something to blow the particles away. I think the rover was doing some drilling at that location. I don't know the days. Maybe a spinning drill test blew the particles around.
I don't know the answer to that one.
Orbital instruments had detected olivine in this area. And detected the presence of large amounts of hematite. That is one reason this location was chosen for Opportunity. Olivine in contact with water breaks down into a number of compounds, including hematite. That is a god indicator that at one time there was a large presence of water.
they expected Opportunity to find hematite. And it did. almost immediately. I think it was on sol 3. Opportunity used large airbags to reduce the impact on landing. It basically bounced around until it stopped, deflated the airbags, opened a container, and the rover drove out.
The airbags left bounce marks. Flat marks on the pebbled surface. They measured the disturbed and undisturbed areas with a number of instruments, including the Miniature-Thermal Emission Spectrometer. The Mini-TES is used to determine the composition of materials and compounds. In the disturbed area it found no hematite. In the undisturbed area it found hematite.
That was the same process used to determine the composition of the "blueberries". The rover drove to a place called the "berry bowl" where there are a lot of these spherules. It took measurements where there is a high concentration of the spherules and and place next to it that has none. Compare the two and there is the tell-tale graph of hematite. If these were mushrooms, presumably that graph would have been completely different.
These are all interesting observations, although I would say that if those processes have been going on for millions years, I would expect to see more spherules.
Perhaps its a dynamic thing, an aspect of, or cycle in the Martian weather - the normal winds blows sand and dust away exposing these spherules and then a honking great global dust storm comes along every five and a half years and covers them all up again.
As soon as you see "Rhawn Joseph" listed on a paper it can be dismissed as junk.
Many of the spherules are not covered in sand or dust as the picture in this thread shows. Many are just laying around on rocks and the surface. Of course, many are also covered or partially covered by sand or dust because there is sand and dust that gets blown around on Mars.
You are looking at one set of pictures of a small 2 inch area. Opportunity took dozens or maybe even hundreds of pictures of these spherules. They are all over the place. In sand, in dust, on rocks. They are all over the place.
The pictures you are looking at and that are in the paper are just a small fraction of these pictured that were pulled out by a crank to support his on-going claim that there are mushrooms or fungi or fields of skulls or some other evidence of life on Mars that NASA is covering up.
With the wind storms on Mars, surely some of these spherules occasionally get covered up. Some get uncovered.
The evidence suggests that it is a surface layer of these spherules. A dusty sandy red surface gets covered with a bunch of grey BBs. Bounce a big balloon on the surface, they get kicked away and no BBs on that mark. Blow a bit of wind, some BBs become slightly more visible.
Yeah, the overall concept is right, and the evidence seems to support what you say here with one exception... These photos were taken on Sol 1145 and 1149 on the north side of Victoria crater. Opportunity landed on Sol 0, three years and two months earlier, and over 15km away at Eagle Crater.
None of this makes me any less interested in what is happening.
You completely lost me. I don't understand how the different dates matter. Opportunity photographed and explored hematite and these spherules on sol 3 and sol 1149 ad beyond. For years. The only evidence of growing in all that is solely these two pictures. That claim ignores absolutely all the other evidence.
We must weigh the evidence:
1. Olivine rich landscape. Orbital signifiers of high hematite presence. Similarity to Utah Hematite concretions. Grey color consistent with hematite. Distribution consistent with hematite concretions and not at all with mushrooms. Thermal emission spectrometry analysis that confirms lab established signature of hematite.
OR
2. These pictures kind of look like mushrooms.
Weigh the evidence.
ETA: also the sand we're now seeing seems to be a lighter colour than the (somewhat courser?) sand that previously covered it. My guess is that the second photo is how it usually looks, the first is the exception.