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Old 12-04-2017, 11:30 PM
 
Location: PRC
3,240 posts, read 3,363,801 times
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What you are all describing are aspects of "weathering" we know here on Earth. The water gets into cracks in the rock and expands as it freezes then thaws, then freezes and expands again.

However, we do not see this kind of weathering on Mars in the images sent back from the rovers. We see cracks in a few rocks, yes, but we dont see the weathered rock which has split in two just lying there in two pieces. In fact, as far as weathering goes, we dont even see the pile of concretions lying at the base of rocks where they are supposed to be encased. We do see examples of a few concretions IN rocks, but we do not see them lying at the base of rocks where they have been "weathered" out - which is the official explanation as to how the appear in so many places in such numbers. Certainly we do not see concretions lying on the ground in piles near the rocks they have been 'weathered' out of. Not enough to cause the millions and millions of concretions we have seen on the ground in some areas of Mars. In my non-scientist view they are not hematite or similar concretions.

If this 'weathering' was going on, on Mars, then it would be shown in the rover images. This water getting into cracks, freezing and thawing would be happening many, many times over the millions of years. I do not see any evidence of this 'weathering' you are suggesting is happening.

Quote:
Most are neither unidentified, nor flying. Ever wonder why the vast bulk of astronomers, both amateur and professional never report UFOs? Because we know what we are looking at.
NO. You may be able to identify stars and planets, but you cannot identify the craft we see in the skies which do not behave as satellites or planes. They are probably mainly secret military craft. Astronomers are generally not looking at the wider skies but are looking at specific areas and specific planetry items. Just because you may be an expert in astronomy does not make you an expert in identifying other things.

Quote:
It's sound science to fill out the basics first, and then go chasing after what looks "interesting". Geologists right here on Earth map out their research area in a structured manner. It's hard to say if a feature is even to be considered interesting at all until you have an idea of the environment. I have no doubt that people are very carefully allotting the rovers' time.
I think it is very telling that you are quite content to allow these one-off events to pass by without investigation. It is unlikely that the rovers will travel in any area again so the opportunity to investigate anything which is unusual should not be missed. After all these rovers have trundled around Mars for so long now, are you telling us they still do not have an idea what the environment is like?

IF the rovers time is so carefully allotted as you suggest, then maybe we should get some rules of engagement and what priorities the scientsist have when determining exactly what is 'interesting' and what is not within the mission and extended-mission objectives. Currently the rover teams are laws unto themselves and appear to be taking many pictures of uninteresting things willy-nilly and leaving many unexplored things behind. I assume also that each transmission costs a lot of money and takes valuable energy to send and receive so I would expect that to be very carefully regulated.
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Old 12-05-2017, 01:23 AM
 
5,205 posts, read 8,209,144 times
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Quote:
Originally Posted by ocpaul20 View Post
What you are all describing are aspects of "weathering" we know here on Earth. The water gets into cracks in the rock and expands as it freezes then thaws, then freezes and expands again.

However, we do not see this kind of weathering on Mars in the images sent back from the rovers. We see cracks in a few rocks, yes, but we dont see the weathered rock which has split in two just lying there in two pieces. In fact, as far as weathering goes, we dont even see the pile of concretions lying at the base of rocks where they are supposed to be encased. We do see examples of a few concretions IN rocks, but we do not see them lying at the base of rocks where they have been "weathered" out - which is the official explanation as to how the appear in so many places in such numbers. Certainly we do not see concretions lying on the ground in piles near the rocks they have been 'weathered' out of. Not enough to cause the millions and millions of concretions we have seen on the ground in some areas of Mars. In my non-scientist view they are not hematite or similar concretions.

If this 'weathering' was going on, on Mars, then it would be shown in the rover images. This water getting into cracks, freezing and thawing would be happening many, many times over the millions of years. I do not see any evidence of this 'weathering' you are suggesting is happening.
With regard to the cracked rock, not every rock on Mars is going to have hematite "Martian Blueberries", and not every rock is going to be examined in detail. Are you suggesting that there's no evidence of weather on Mars? That Mars doesn't have any weather? While you're criticizing opinions, you're not exactly coming up with any suggestions, although you alluded to possible entities.

Okay, we don't see the rock laying there in two pieces. We don't know anything about the rock. Just because there's a crack in it, doesn't mean the rock is completely split in two with both halves laying over. We don't know how deep the crack is. We don't see the other side of the rock, so it might not be cracked all the way through. Earlier you were mystified about the dark area you described as a "hole". I'd like to know more about the triangular features on that rock. There's at least one, and maybe another one. Is the rock some kind of lava? Could it be a piece of the asteroid that formed the crater? Who knows? You've asked what people here think about it. What's your opinion about it?

Quote:
Originally Posted by ocpaul20 View Post
I think it is very telling that you are quite content to allow these one-off events to pass by without investigation. It is unlikely that the rovers will travel in any area again so the opportunity to investigate anything which is unusual should not be missed. After all these rovers have trundled around Mars for so long now, are you telling us they still do not have an idea what the environment is like?

IF the rovers time is so carefully allotted as you suggest, then maybe we should get some rules of engagement and what priorities the scientsist have when determining exactly what is 'interesting' and what is not within the mission and extended-mission objectives. Currently the rover teams are laws unto themselves and appear to be taking many pictures of uninteresting things willy-nilly and leaving many unexplored things behind. I assume also that each transmission costs a lot of money and takes valuable energy to send and receive so I would expect that to be very carefully regulated.
I think it is very telling that you feel everyone is suppose to agree with you and demand that JPL investigate every rock you feel is worthy of examination. I agree there are a lot of interesting features the rovers have spotted. What do you want them to do, go over and take a closeup peek at everything? I wish that were possible. You can always contact them and tell them all the interesting opportunities they're missing. Keep in mind that some features are off the path and too hard to reach. As it is, at least one of the wheels is showing wear from the rugged terrain.

Here's the problem. If they responded to every request made by people, the rover would still be at the base of Mt Sharp. And that's not very realistic. By the time the images are released online for viewing, the rover has probably moved on. About the only time the rover is parked is when Mars is on the opposite side of the Sun from us and out of range for communication. They're not exactly going to park the rover at a given spot for 6 months or a year to search every rock that's there. Currently, Curiosity is heading up the mountain, as far as it can, to look at different layers. A good part of that it to get an idea of how long the crater was filled with water, and how deep it was. There have clearly been signs that flowing water was present in the past. The 2020 rover will take the next steps in exploring the planet.
https://mars.nasa.gov/msl/mission/science/objectives/

https://mars.nasa.gov/MSL/mission/science/goals/

https://mars.nasa.gov/mars2020/missi...ce/objectives/

https://mars.nasa.gov/mars2020/mission/science/goals/
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Old 12-05-2017, 04:24 AM
 
3,426 posts, read 2,791,198 times
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Quote:
Originally Posted by ocpaul20 View Post

NO. You may be able to identify stars and planets, but you cannot identify the craft we see in the skies which do not behave as satellites or planes. They are probably mainly secret military craft. Astronomers are generally not looking at the wider skies but are looking at specific areas and specific planetry items. Just because you may be an expert in astronomy does not make you an expert in identifying other things.
I am the director of the Louisville Astronomical Society James G. Baker Center for Astronomy, and I can say with no hesitation that you don't know what you are talking about. Our open roof observatory lets us see the entire sky while we are imaging specific areas. And many of our members are ex-military, some ex-air force. And so you are wrong that we are not expert in identifying other things. No one observes the sky, especially the night sky, including things in and just above the atmosphere, more than amateur astronomers do. No one. Resorting to UFOs and ET to explain what we see in the night sky is lazy thinking and unprofessional.
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Old 12-05-2017, 06:56 AM
 
Location: PRC
3,240 posts, read 3,363,801 times
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Quote:
With regard to the cracked rock, not every rock on Mars is going to have hematite "Martian Blueberries", and not every rock is going to be examined in detail. Are you suggesting that there's no evidence of weather on Mars? That Mars doesn't have any weather? While you're criticizing opinions, you're not exactly coming up with any suggestions, although you alluded to possible entities.

Okay, we don't see the rock laying there in two pieces.
...And my opinion does not count for anything since when it is offered, it is then criticised. This you know, so do not ask me for suggestions.

I was not trying to argue that the rock in the initial picture on this thread should or should not be in 2 pieces, but that in general, we dont see this type of weathering in the rover images, pieces of rock where the crack has become a split and the rock has broken into two pieces. If there was obvious weathering as it happens on Earth, then I would expect to see this in the rover pictures more often.

It is true, I do not feel there is much evidence of weathering on Mars. We have been told that the wind is weak, the atmosphere is not so harsh as it is on Earth and the water is kind-of scarce so the same rough processes which shape our world here do not do the same thing on Mars. In the pictures from the rovers, I do not see much evidence of environmental change which could account for weathering as we know it.

The only examples I see would be small dust-sized grains of sand which appear to be blown about into very small sand dunes between and up against rocks by the weak winds. People mention the stronger dust-devil winds - the NASA movies(gifs) of those moving across the plains. There is no evidence (larger sand piles between rocks, blown blueberries, etc) of those same dust-devil winds in the rover images, so where are they? Where is evidence of the year-long giant dust storm which raged on Mars a number of years ago?

Talking of water on Mars, this looks to me as if there is a mud flow(red arrows) over the rock, the shadow of the rover(yellow arrows) and some kind of oval indentation AFTER the water/mud has flowed(blue arrow). Obviously, my interpretation may be flawed, but from an Earthly perspective, this is what it looks like to me.
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Old 12-05-2017, 11:34 AM
 
33,763 posts, read 17,301,322 times
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Quote:
Originally Posted by ocpaul20 View Post
I think it is very telling that you are quite content to allow these one-off events to pass by without investigation. It is unlikely that the rovers will travel in any area again so the opportunity to investigate anything which is unusual should not be missed. After all these rovers have trundled around Mars for so long now, are you telling us they still do not have an idea what the environment is like?
We don't yet know what counts as unusual. Seriously, this is the difference between the amateur and the professional in geological surveys - in most science, actually. The boring groundwork is the foundation and is where you spend your resources.

Quote:
IF the rovers time is so carefully allotted as you suggest, then maybe we should get some rules of engagement and what priorities the scientsist have when determining exactly what is 'interesting' and what is not within the mission and extended-mission objectives.
A handy list of Curiosity's objectives here:

https://mars.jpl.nasa.gov/msl/missio...ce/objectives/

Quote:
Currently the rover teams are laws unto themselves and appear to be taking many pictures of uninteresting things willy-nilly and leaving many unexplored things behind.
Where do you get these ideas? The Rover teams are directed by the USGS Astrogeology Science center, manned by people who spent decades of their lives on planetary geology. They know their stuff.

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I assume also that each transmission costs a lot of money and takes valuable energy to send and receive so I would expect that to be very carefully regulated.
Gathering data and not transmitting them would be the biggest waste imaginable.
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Old 12-05-2017, 05:38 PM
 
Location: PRC
3,240 posts, read 3,363,801 times
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After years of training and being the top scientists in their fields, I have no doubt that the scientists do indeed know what they are talking about. I dont mean they are useless but that their hands are somewhat tied in what they can say and do.

Unfortunately, the scientists do not always have the last word on what is released and what is not. When people work for the government, they have to follow government orders not necessarily ones which seem sensible to others like you and me outside the authorities themselves.
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Old 12-05-2017, 10:38 PM
 
5,205 posts, read 8,209,144 times
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Originally Posted by ocpaul20 View Post
...And my opinion does not count for anything since when it is offered, it is then criticised. This you know, so do not ask me for suggestions.
There are two different kinds of criticism. One is related to differing opinions like a debate. The other is more of an unnecessary slam. Don't take things so personal. You have the choice to weed through the posts to determine what's of the most interest to you. There's nothing stopping you from voicing your opinion. If you're not willing or not able to offer your views, then what's the point of this thread? If other counter your views with other options, there's nothing wrong with that. That's a part of how we learn about new things. You asked the question of what would cause a hole in that rock. You got several plausible answers. And yet, the image doesn't show a hole. It just shows a shadowed area which could be a depression in the rock and the crack.

Quote:
Originally Posted by ocpaul20 View Post
I was not trying to argue that the rock in the initial picture on this thread should or should not be in 2 pieces, but that in general, we dont see this type of weathering in the rover images, pieces of rock where the crack has become a split and the rock has broken into two pieces. If there was obvious weathering as it happens on Earth, then I would expect to see this in the rover pictures more often.
So then your question is about evidence (or lack of) weathering? It's known that there is a small amount of moisture in the atmosphere. Not much, but enough to settle into tiny, hair-sized cracks or fractures that can freeze during the cold temperatures. That process year after martian year can build up gradually making the crack larger, perhaps taking millions of years or even less depending on the composition of the rock. There are certainly weird polygon soil fractures within view of the Phoenix Lander near the Northern Ice Cap. There might be a lot more cracked rocks that have been captures by the rover. Scan through some of the photos in detail.

Quote:
Originally Posted by ocpaul20 View Post
It is true, I do not feel there is much evidence of weathering on Mars. We have been told that the wind is weak, the atmosphere is not so harsh as it is on Earth and the water is kind-of scarce so the same rough processes which shape our world here do not do the same thing on Mars. In the pictures from the rovers, I do not see much evidence of environmental change which could account for weathering as we know it.
There are loads of signs of weathering on Mars. What do you think causes the ice caps to grow and shrink, or wind to blow? What causes those large dust devils to streak across the surface? It's all related to weather.

The Curiosity rover measured a top wind speed of about 60 mph (about half the speed of a hurricane on Earth). I agree, that a lot of things are indeed different on Mars. It isn't the Earth. One difference is that the air pressure on Mars is about 0.6% of the pressure on Earth at sea level. So while the wind might be fast on Mars, it isn't as forceful as strong winds on Earth. The atmosphere on Mars is very thin and weak.
https://en.wikipedia.org/wiki/Atmosphere_of_Mars

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Originally Posted by ocpaul20 View Post
The only examples I see would be small dust-sized grains of sand which appear to be blown about into very small sand dunes between and up against rocks by the weak winds. People mention the stronger dust-devil winds - the NASA movies(gifs) of those moving across the plains. There is no evidence (larger sand piles between rocks, blown blueberries, etc) of those same dust-devil winds in the rover images, so where are they? Where is evidence of the year-long giant dust storm which raged on Mars a number of years ago?
There are some pretty hefty sand dunes on Mars, some around 200 feet high. Below is a link showing sand ripples by Curiosity. They're small, but is shows that wind causes sand to move. The other link show wind sculpted sand dunes. Keep in mind this is in Gale Crater.
https://www.cnet.com/news/nasa-mars-...hifting-sands/
https://www.jpl.nasa.gov/news/news.php?feature=6551

The last global dust storm on Mars was in 2007. Other storms have been noted in 1977, 1982, 1994 and 2001. It's been a while since the last major dust storm. Another was predicted for 2016 or 2017, but so far, nothing as far as I can tell.
https://mars.nasa.gov/news/study-pre...storm-on-mars/

The Martian Blueberries are dropped from being encased in rock to the ground. It's due to erosion. Some are too big to easily blow around like sand, although there are plenty of flat cracked rocks on the ground filled with blueberries. Where blueberries (hematite) are found indicate the presence of water at some point in the past. Not every location on Mars was covered by water. Currently, the missions of the rovers have been to "follow the water". It's one reason Gale Crater was chosen. Indications that moving water occurred on Mt Sharp is shown by trails of smooth rocks that are only formed by the action of moving water. We can presume that flowing streams were present on Mt Sharp in the past, enough to cause rocks to be smoothed by tumbling and warn by liquid water.

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Originally Posted by ocpaul20 View Post
Talking of water on Mars, this looks to me as if there is a mud flow(red arrows) over the rock, the shadow of the rover(yellow arrows) and some kind of oval indentation AFTER the water/mud has flowed(blue arrow). Obviously, my interpretation may be flawed, but from an Earthly perspective, this is what it looks like to me.
The photo you posted could be hardened mud. If you look off the flat rock to the upper left corner, you can see more stones that appear to be smooth, along with what appear to be some blueberries mixed in. Or it might be that what appears to be a mud track, is just due to fractures in the flat rock filled in with hardened sand and blueberries. Just saying. Where did you find that photo? I'd like to have a better look at it.
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Old 12-06-2017, 09:11 AM
 
Location: PRC
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Good luck with finding anything worth looking at. The link below is worse than useless for close-up examination and is only good for a summary of the image.

I am pretty sure the photo I posted is from the PDS because usually the images posted for the public are JPG files and compressed and degraded as the link below. The photos in the PDS are supposed to be better quality but from the ones I have seen are often not better at all.

This particular one was a gif inside the PDS img file as far as I could tell when I extracted it some time ago. I wrote the number on the image itself for my records. Here are the details.

https://mars.nasa.gov/mer/gallery/al...8P1214L0M1.JPG

Rover Opportunity
Sol 37
Site 05
Camera Front HAZCAM

This is version 1 of a photograph produced for M - MIPL (OPGS) at JPL on Tue, 2 Mar 2004 GMT at 06:13 which is Sol 37.

I believe the PDS link is this, although I have trouble accessing it from here.
http://pds-imaging.jpl.nasa.gov/data...14l0m1.img.jpg

Last edited by ocpaul20; 12-06-2017 at 09:19 AM.. Reason: add pds link
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Old 12-06-2017, 03:47 PM
 
5,115 posts, read 4,721,701 times
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Quote:
Originally Posted by ocpaul20 View Post
Talking of water on Mars, this looks to me as if there is a mud flow(red arrows) over the rock, the shadow of the rover(yellow arrows) and some kind of oval indentation AFTER the water/mud has flowed(blue arrow). Obviously, my interpretation may be flawed, but from an Earthly perspective, this is what it looks like to me.
I was wondering about the scale of the mud flow in the image. Since its already been pointed out that the rover is casting a shadow, it appears that the mud flow is about a foot or less in length. That's using the size of a rover wheel for comparison purposes - the round shadow is being cast by the wheel.

If it is a mud flow, then its a very small one. And I'd opine that it's more likely just some martian dirt that was kicked up by the rover's wheel.
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Old 12-06-2017, 04:42 PM
 
5,205 posts, read 8,209,144 times
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Quote:
Originally Posted by ocpaul20 View Post
Good luck with finding anything worth looking at. The link below is worse than useless for close-up examination and is only good for a summary of the image.

I am pretty sure the photo I posted is from the PDS because usually the images posted for the public are JPG files and compressed and degraded as the link below. The photos in the PDS are supposed to be better quality but from the ones I have seen are often not better at all.

This particular one was a gif inside the PDS img file as far as I could tell when I extracted it some time ago. I wrote the number on the image itself for my records. Here are the details.

https://mars.nasa.gov/mer/gallery/al...8P1214L0M1.JPG

Rover Opportunity
Sol 37
Site 05
Camera Front HAZCAM

This is version 1 of a photograph produced for M - MIPL (OPGS) at JPL on Tue, 2 Mar 2004 GMT at 06:13 which is Sol 37.

I believe the PDS link is this, although I have trouble accessing it from here.
http://pds-imaging.jpl.nasa.gov/data...14l0m1.img.jpg
Thanks. Both links worked for me. That puts things in a better perspective. Opportunity (and Spirit) never descended into any craters. Spirit tried to, but got fatally bogged down in sand near the top of the crater. They basically roamed on the surface. We can see in the link photo that the land is relatively flat. We can also see more of the flat rocks in the area. That rules out falling water and probably streams. The surface of the areas both rovers explored are thought to have been covered by water, possibly a shallow ocean, as there were lots of hematite blueberries in those regions.

Looking at the other flat rocks in the photo, I'm be inclined to think what appears to be a muddy track is just cracks in the rock filled with sand, dust and hematite balls, possibly kicked up by the rover's wheel (I not sure about that though). Looking at the other similar rocks in that photo, and we see those also have similar layers, some of which are somewhat scooped out, probably by wind and sand over time. It's not the only time such rocks have been spotted. One of the problems with the blown-up photo (with the arrows) is that it's a little blurred.

However, that doesn't answer the split rock. That one was by Curiosity, correct? That rock appears to be different from the flat surface rocks, although we do see some rocks with layering. There's a lot more rocky debris of various sizes around that appear to be shattered. I'd still stand on the idea that the rock in question was probably split due to water and ice that seeped in through tiny pores and cracks. I originally suggested water vapor, but maybe not vapor, although it's not too much of a stretch for such moisture to condense and seep into those cracks. Regardless, the process is known as Physical or Mechanical Weathering, and in particular is called "Frost Shattering". Frost Shattering can split rocks by liquid water that seeps in, then freezes when temperatures drop. The ice expands forcing the crack to get a little bit wider, even cleaving them in two over time by freezing and thawing.

Granted, this is on Mars, and the examples below show this weathering here on Earth. But the examples can give us an idea about the geology on Mars. There may be differences, but there are also similarities.

Check Photo #24 in this link
https://matadornetwork.com/trips/60-...he-world-pics/

Scroll down to Frost Weathering in this link
Weathering | Geology Page
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