Valles Marineras Origin and Origin of Asteroid Belt Linked?

  • Context: Undergrad 
  • Thread starter Thread starter elroyjetsn
  • Start date Start date
  • Tags Tags
    Asteroid Belt Origin
Click For Summary

Discussion Overview

The discussion revolves around the origin of Valles Marineris on Mars and its potential connection to asteroid impacts, as well as the formation of crater chains on asteroids like Phobos and Vesta. Participants explore theories related to geological features, impact events, and tectonic activity, incorporating both observational and speculative reasoning.

Discussion Character

  • Exploratory
  • Debate/contested
  • Technical explanation

Main Points Raised

  • One participant suggests that Valles Marineris may have formed from a low-angle impact by an asteroid or comet, comparing it to the effect of shooting BBs into fruit.
  • Another participant counters that large impacts typically create circular craters and proposes that Valles Marineris is more likely the result of tectonic activity due to Mars' geological history.
  • A participant notes the presence of a large crater offset from Valles Marineris and speculates about the impact of planetary rotation on the trajectory of the impactor.
  • Some participants discuss the geological processes that could lead to the formation of features like Valles Marineris, emphasizing the role of tectonic shifts over time.
  • There is speculation about crater chains on asteroids being formed by ring fragments, with a suggestion that similar processes could occur on Mars due to its low-density atmosphere.
  • One participant expresses skepticism about the impact of surface events on underlying geological currents, suggesting that tectonic shifts are driven by deeper mantle processes.

Areas of Agreement / Disagreement

Participants express differing views on the formation of Valles Marineris, with some supporting the impact theory and others favoring tectonic explanations. The discussion remains unresolved, with multiple competing theories presented.

Contextual Notes

Participants acknowledge the complexity of geological processes and the limitations of their hypotheses, noting that the relationship between impact events and tectonic activity is not straightforward.

elroyjetsn
Messages
10
Reaction score
0
The aerial view of Valles Marineras has a strangely familiar look to it. As a kid I would shoot BB's at all sort of fruit and mud and stuff. Sometimes I'd hit a rotten apple or tomatoe with a glancing shot that would rip open a gaping tear for a distance as the BB would enter, force material out of the fruit thru the tear and afterword the tear would fill with soft material and juice(if the tear is facing up). I suspect that a similar event has occurred on Mars at some time in the past resulting in a trauma zone that is now called, "Valles Marineris".

Of course this would be a "punch-through" of a much greater scale. An asteroid or comet striking the planet at a low angle of insidence that is large and dense enough may have penetrated the lithosphere and blasted through the softer interior opening a huge tear in the lithosphere sending a 'rooster tail' of ejecta all around and into open space. The impact object would have no doubt been reduced to a much smaller size by the time it exited the lithoshpere again that is if it was able to do so at all.

Has such a theory ever been suggested?

Wayne
 
Astronomy news on Phys.org
elroyjetsn said:
The aerial view of Valles Marineras has a strangely familiar look to it. As a kid I would shoot BB's at all sort of fruit and mud and stuff. Sometimes I'd hit a rotten apple or tomatoe with a glancing shot that would rip open a gaping tear for a distance as the BB would enter, force material out of the fruit thru the tear and afterword the tear would fill with soft material and juice(if the tear is facing up). I suspect that a similar event has occurred on Mars at some time in the past resulting in a trauma zone that is now called, "Valles Marineris".

Of course this would be a "punch-through" of a much greater scale. An asteroid or comet striking the planet at a low angle of insidence that is large and dense enough may have penetrated the lithosphere and blasted through the softer interior opening a huge tear in the lithosphere sending a 'rooster tail' of ejecta all around and into open space. The impact object would have no doubt been reduced to a much smaller size by the time it exited the lithoshpere again that is if it was able to do so at all.

Has such a theory ever been suggested?

Wayne
Unfortunately, it doesn't work like that for larger collisions. Basically, when collisions get big enough, they tend to make large, nearly-circular craters no matter the impact angle. More likely Valles Marineris was the result of tectonic activity in Mars' past. Mars, being smaller, has cooled faster than the Earth, and has less weathering. As a result it tends to have much larger tectonic features.
 
Chalnoth said:
Unfortunately, it doesn't work like that for larger collisions. Basically, when collisions get big enough, they tend to make large, nearly-circular craters no matter the impact angle. More likely Valles Marineris was the result of tectonic activity in Mars' past. Mars, being smaller, has cooled faster than the Earth, and has less weathering. As a result it tends to have much larger tectonic features.

On the West end of the valley there's a pretty large crater that somewhat offset from the "tear". But, I'm thinking an event of that magnitude might have taken an hour or so to play out and the planet's rotation would have distorted the trajectory. The region designated, "Noctis Labarynthus" being a possible entry point. The East end(Eos Chaos region) of the valley there appears to be a enormous amount of material flowing in all direction and further West there a large belt of impact craters, consistent with such an event. I suppose that may be circumstantial?

I speak as an amateur biologist with an interest in physics. LOL.
 
elroyjetsn said:
On the West end of the valley there's a pretty large crater that somewhat offset from the "tear". But, I'm thinking an event of that magnitude might have taken an hour or so to play out and the planet's rotation would have distorted the trajectory. The region designated, "Noctis Labarynthus" being a possible entry point. The East end(Eos Chaos region) of the valley there appears to be a enormous amount of material flowing in all direction and further West there a large belt of impact craters, consistent with such an event. I suppose that may be circumstantial?

I speak as an amateur biologist with an interest in physics. LOL.
Yeah, I suspect it's largely a coincidence. Such geological features generally occur because of the drifting of the planet's crust, which is driven by the currents in the mantle below the crust. An impact on the surface isn't going to have much of an effect on those underlying currents.

Now, such an energetic event may potentially have an impact on when a tectonic shift occurs, but it doesn't really change the underlying causes of the shifts, so I don't think it can be responsible for a feature like a canyon, especially as such features are built up from a large number of tectonic shifts produced over a large span of time.
 
We are speculating on the same thing a bit about the "crater chains" on Phobos, Vesta, and some other asteroids.

We have come to the conclusion they are formed by ring fragments, with the orbit decaying slowly enough to allow individual rocks to come in and bounce along the surface , then ejecting or slowing enough to finally plow into the surface.
There does seem to be a few of the chains that tail off at a parabola like a stone skipping.

Mars has such a low density atmosphere, it is not totally outside the realm of possibility. One of the reasons it is so hard to land there.
 
Hypervelocity said:
We are speculating on the same thing a bit about the "crater chains" on Phobos, Vesta, and some other asteroids.

We have come to the conclusion they are formed by ring fragments, with the orbit decaying slowly enough to allow individual rocks to come in and bounce along the surface , then ejecting or slowing enough to finally plow into the surface.
There does seem to be a few of the chains that tail off at a parabola like a stone skipping.

Mars has such a low density atmosphere, it is not totally outside the realm of possibility. One of the reasons it is so hard to land there.
Not for a feature that big, though.