The mainstream consensus seems to be that "Valles Marineris is a large tectonic "crack" in the Martian crust, forming as the planet cooled, affected by the rising crust in the Tharsis region to the west, and subsequently widened by erosional forces." http://en.wikipedia.org/wiki/Valles_Marineris. However when I look at it, I can't help but think it looks like mars was sideswiped. Would not that sort of collision be sufficient to change the rotation of mars and possibly strip away some atmosphere and a large porttion of water at the same time?

Is there anyone in the scientific community that has put forth this idea? Anyone on UM have any input?

I fail to see where you see any evidence for an impact. Even a side swipe would lead to the virtually instantaneous vaporisation of the impacting body and of the area of Mars where the impact occured. This is unavoidable as kinetic energy would be converted to heat energy on impact.

The result of this would be the familiar impact crater shape (albeit more ovoid than circular) that we see on so many solar system bodies.

The sort of "graze" that you seem to be imagining is simply not possible.

Well looking at those pic's I don't think it's an impact, as most impacts leave a crater. This to me looks like massive mars versions of the Grand Canyon much larger versions. The grand canyon was formed by water and I don't know if at one point mars had enough water to do that but I'm no scientist...

Good one Waspy, beat by a few seconds LOL

Question for you Waspy, do think this could have been done with water ?

I'm not claiming scientific eveidence, I just thought that it "LOOKED" like a swideswipe to me, and I was wondering if I was the only one who thought so. (not claiming aliens
either lol) Fair enough if you understand the science behind it all. but what if the object was much larger than a typical asteroid, say near as large as Mars itself. While I'm
speculating (please bear with me, I'm just having fun), what if the other body merely grazed the atmosphere of Mars, but did not come into contact with Mars itself?

Then it is possible that both objects would be destroyed. It is likely that a new body would reform form the debris but as it would have a new surface then there would be no scar.



Then either the object would vaporise in the atmosphere leaving no no crater but maybe some superficial damage on the surface (as happened at Tunguska, 1908) or the the object would bounce off the atmosphere back into space. Either way you would not get a feature like the Valles Marineris.

Incidentally, while you are speculating you have to come up with an explanation for the actual structure of the Mariner Valley. It is not a single straight feature but has complex structure involving many smaller branches. How does that fit in with your hypothesis?

Well I was merely speculating that the initial cause might have been a sort of celestial fender bender. Of coarse after that point all other manner of forces may have worked on it. The fact that there appears to be liquid erosion as a shaping factor is something that says there was plenty of liquid water SINCE the initial cause of the feature. That in itself may put another hole in my idea. The cool thing for me, and why I started this thread in the first place, is to have people like yourself to bounce my idea off of to see if there is any validity to it. I tried to find some info on the topic, but not having a particularly scientific mindset or education, I'm limited on how to dig up the stuff I can understand from an artists kind of view point. That's where you and many others here on UM have truly helped me. Thanks. I still wonder how the valley was formed, its such a massive feature. There was mention in the Wiki article of tectonics, but I remember hearing that there were no tectonics on Mars? Are you absolutely certain that there could be no conditions other that tectonics to form the valley?

I wonder if the wide part in the middle could have been a crater that was acted upon by other forces (I don't know, I'm just wondering), that produced what we see today?

Looking at the Grand Canyon from Google Earth, I don't think it looks all that similar. I think that even though erosion probably played a role, There was something much
larger to create the valley in the first place. This thing makes the Grand Canyon look like a pothole by comparison.

Why would it? The Grand Canyon is a valley cause by erosion of an active river, Valles Marineris almost certainly isn't. The Mariner Valley is more like East Africa's Great Rift Valley than the Grand Canyon.


Agreed, you actually gave the believed method of origin for the Mariner Valley in your first post, why are you ignoring it now?



Again agreed but what has scale got to do with it?

For a tiny planet Mars does things on a big scale, take a look at the Tharsis volcanoes and the size of them. I see no inconsistencies with the forces that where capable of producing a volcano 3 times taller than Everest being able to form a huge Rift Valley.

Speculation is a great thing, but there comes a time to accept that a hypothesis is simply not backed up by the evidence.

Actually I was responding to Silver Thong's post, who said it looked similar to the Grand Canyon, when I pointed out that it didn't look all that similar. I commented that it had to be something more than erosion, in answer to that specific comment. That's not to say I'm ignoring the believed method, simply that erosion is not it. Scale means that the forces in play are greater than what erosion alone could produce, or what we commonly see here on earth. The comment about the feature making the Grand Canyon look like a pothole by comparison, is just to say it so immense that it seems incomparable to our Grand Canyon. As a side note, I had seen the GC when I was a boy . Ten years ago I had gone to visit again. When I walked to the rim, the sight literally brought tears to my eyes, it impressed me so. Now I'm curious to check out East Africa's Great Rift Valley. Ok, my hypothesis is not backed up by the evidence. I ask you this - It seems I have heard that there are no tectonics at work on Mars. Apparently there was tectonics early on, why not now? Also, why are the features, such as Olympus Mons, so dramatically larger on Mars. I'm just curious and want to talk to people who take interest in and can answer such things. Peace.

I'm afraid I've run out of talent here. I just don't know.

I'm no Geologist, so this is just speculation on my part.
It's true that Olympus Mons is so much larger than Everest and that Valles Marineris is so much deeper than the Grand Canyon. But bare in mind that Mars has no sea level. If you take away the sea level here on Earth, how high would Everest be then? Also, how deep would Valles Marineris be compared to the Laurentian Abyss or the Mariana Trench? When compared with these Earth features, minus the sea level, then the Martian features don't seem quite so impressive anymore.

Wow, great point. Water changes everything. I can't help but wonder what Mars was like with water then. How high would Olympus Mons have been above Martian sea level?
If I, as a complete layman, can get excited about Mars, I wonder what is must be like to be on the Mars exploration teams.

Never stop looking and wondering StrangeF8 its what makes us human,and this is how we learn,Keep asking all the time in here.Someone will be more than freindly to your questions. I think its great to question and enjoy the mysteries and the unexplained.Good to read your post. I think Mars is a key to our future.

Thanks for the freindly encouragement. If we don't destroy ourselves first Mars will be the key to our future.

also Mars has a lighter gravity than Earth, so features like volcanoes can be taller...

Its an Electrical Scar as far as Electric/Plasma Cosmology indicates.

Actually no it doesn't. Whilst it is true that yo can point out that Everest is the highest mountain on Earth it is also possible to measure how tall it is. That is the distance from its base to its peak. If you do that with mountains on Earth then Everest loses it's place as the tallest mountain, Mauna Kea, the Hawaiian island is taller as it's base is below the sea. From base to peak it is 10,203 meters but as it's base is on the Pacific Ocean floor the first 5,998 meters are below mean sea level. Compare this mighty volcano to that of Olympus Mons, which is 2.6 times taller than Mauna Kea and you see that sea level has nothing to do with this monstrous size of this volcano.

The same can be said of the vast size of the Mariner Valley, it's huge in comparison to any similar feature on Earth regardless of sea level. The point I made still stands, the forces that were at work that caused Olympus Mons (and remember Olympus Mons is just the largest of a series of vast volcanoes in the Tharsis region) are more than capable of creating the Valles Marineris.


Indeed I agree, however sometime the lesson that is learned is that the hypothesis is wrong. This is the way science progresses. Observation, hypothesis, more observation. If the observations do not fit the hypothesis then the hypothesis is dropped and a new one formulated. That is why it is the friendly thing to do to point out why a hypothesis is wrong.

From what I know the answer to this one is heat. Mars does not have plate tectonics, because of this a volcanic 'crack' like Valles Marineris just stays put, the heat continues to escape from the same spot for millions and millions of years. This makes for one great big fissure. This is a pretty well supported hypothesis, based on some things I've read.

Thanks for that answer. Lets see if I understand all of this now. For a variety of reasons it CAN NOT BE the result of a side swipe collision. Water does not have anything to do with the size. Although gravity may contribute, it is heat and the lack of plate tectonics which cause the Valles Marineris and other features on Mars to be so enormous in scale. Still fascinating no matter what the cause. I'm sorry if I as a complete novice when it comes to science, venture into the territory of those well versed. I did not mean to offend or challenge, I was just curious and wondered. Peace.

Scientific ideas need to be challenged, it is part of the process. It certainly does not cause offence. It only becomes problematic when people continue to challenge when the evidence shows them to be wrong, you have the good sense not to do that.

Rather than causing offence this is exactly the sort of thread I like to see, questions asked, answers given and we all learn something along the way. Keep asking and challenging Strange F8.

Perhaps it seems like a challenge when I keep asking until I'm satisfied that I understand. At times, I get consumed with curiosity and have to follow it. Thanks for the dialog and the education.

Not really, main reason why it's larger is the fact that Mars had no tectonic plates throughout most of its history, allowing the volcano to grow larger since it couldn't move unlike most of the volcanoes here on Earth.

I just looked up the word tectonic. I had assumed that it referred to the movement of tectonic plates, so I was confused when the initial explaination I read said the Valles Marineris was a tectonic crack. But as I understood it, there were no tectonic plates on Mars. The word tectonic simply refers to construction. So, while Mars' construction resulted in large features such as Olympus Mons, Earth's construction and subsequent reshaping resulted in an ever changing surface that does not allow feature on the same scale. I shoulda gone to the dictionary in the first place., but I am enjoying this dialog.

New info has come forth about a Mars collision. Curiously, they figured out the impact crater is in the area just west of Valles Marineris. So now I wonder if the VM is not so much a gouge, but a fissure opened up due to the impact.

Here's a link to an article on Nature.com: http://www.nature.com/news/2008/080625/ful...s.2008.916.html

What say you Waspie?

Its still just a theory.

From the article:



The impact theory is being presented as a possible answer to the question of why the Martian crust is thinner in the Northern Highlands than in the Southern Lowlands. There could still be other reasons for the different thicknesses, but the impact theory does present a possible answer.

Also, the theory as presented in the article, makes no reference or connection to Valles Marineris.


Cz

There is a reference to the volcanic mountain range which is at the western end of the VM. The whole picture of coarse is not totally understood. There will be much debate in the scientific community I'm sure. As a science novice, all I can do is read and try to understand what they are saying, but as I Mars buff of sorts, my curiousity is piqued with this new information. Thanks for the response Cz.