Mars's Mysterious Elongated Crater

[Moontanman]

Mars's Mysterious Elongated Crater

 

 

 

 

 

 

ScienceDaily (Aug. 30, 2010) — Orcus Patera is an enigmatic elliptical depression near Mars's equator, in the eastern hemisphere of the planet. Located between the volcanoes of Elysium Mons and Olympus Mons, its formation remains a mystery.

 

 

http://www.sciencedaily.com/releases/2010/08/100827082326.htm

 

 

(oops)

[Knothead]

Mars's Mysterious Elongated Crater

 

 

 

 

 

 

ScienceDaily (Aug. 30, 2010) — Orcus Patera is an enigmatic elliptical depression near Mars's equator, in the eastern hemisphere of the planet. Located between the volcanoes of Elysium Mons and Olympus Mons, its formation remains a mystery.

 

 

http://www.sciencedaily.com/images/2010/08/100827082326-large.jpg

 

 

Couldn't something like that have been formed by a glancing impact many eons ago? It looks like it may have been filled with liquid at one time and has dried out leaving a surface that appears smoother than the surrounding landscape.

[JMJones0424]

Indeed, an oblique impact is one of the likely causes. I think Moontanman meant to include a link to the article, rather than to the picture. The full text can be found here:

http://www.sciencedaily.com/releases/2010/08/100827082326.htm

[Turtle]

Couldn't something like that have been formed by a glancing impact many eons ago? It looks like it may have been filled with liquid at one time and has dried out leaving a surface that appears smoother than the surrounding landscape.

 

Indeed, an oblique impact is one of the likely causes.

 

so no, possibly, and yes. mind you this is a pet peeve of mine & i may carry on a bit. :rant: mind you also i have done a considerable amount of research on this topic over the last several years, so any rebuttle better be well referenced. :P

 

so my first no is, "no, there is no foundation for the idea of a 'glancing impact' in the formation of an impact crater". none, nada, zip, zilch, & not-a-smidgen or a mite. :unsure: at the velocities an object must have to collide with a planet -the velocity range strictly dictated by laws of physics- , an object making contact is going to partly if not wholly vaporize, most certainly largley to completely break up, and possibly but not necessarily bury some remant core piece of most likely nickel & iron. this is high energy impact here, not billard balls or bullets. the energies are literally beyond any experience you have.

 

my maybe is that the crater may have had water, but not necessarily. it could have filled with molten material after impact and certaily would have accumulated dust and so may have filled.

 

finally my yes is that the impact may have been oblique, but this does not equate to a "glancing blow". other than dust & relatively small ejecta (from both the impactor & the planet impacted) escaping into space, an impactor for all intents & purposes is colligated to the planet it impacts.

 

another possiblity worth mention is that the object broke into pieces fairly close to impact and the differentials of drag sorted the fragments & left the stretched crater we see. as with impact crater identification on earth, one would have to visit this site to say anything definitive about what actually happened.

 

that's all i got for now. remember if you see a bright flash in the sky, duck & cover. :(

[Knothead]

so no, possibly, and yes. mind you this is a pet peeve of mine & i may carry on a bit. :rant: mind you also i have done a considerable amount of research on this topic over the last several years, so any rebuttle better be well referenced. :P

 

so my first no is, "no, there is no foundation for the idea of a 'glancing impact' in the formation of an impact crater". none, nada, zip, zilch, & not-a-smidgen or a mite. :unsure: at the velocities an object must have to collide with a planet -the velocity range strictly dictated by laws of physics- , an object making contact is going to partly if not wholly vaporize, most certainly largley to completely break up, and possibly but not necessarily bury some remant core piece of most likely nickel & iron. this is high energy impact here, not billard balls or bullets. the energies are literally beyond any experience you have.

 

my maybe is that the crater may have had water, but not necessarily. it could have filled with molten material after impact and certaily would have accumulated dust and so may have filled.

 

finally my yes is that the impact may have been oblique, but this does not equate to a "glancing blow". other than dust & relatively small ejecta (from both the impactor & the planet impacted) escaping into space, an impactor for all intents & purposes is colligated to the planet it impacts.

 

another possiblity worth mention is that the object broke into pieces fairly close to impact and the differentials of drag sorted the fragments & left the stretched crater we see. as with impact crater identification on earth, one would have to visit this site to say anything definitive about what actually happened.

 

that's all i got for now. remember if you see a bright flash in the sky, duck & cover. :(

 

Foundation? I don't know anything about foundations. Why does it have to be an impact crater. Maybe it's just a groove. It sure looks like something a glancing blow would create.

The edges don't really look as defined as a regular crater.

 

What the heck is the difference between glancing and oblique anyway?

 

Why couldn't something have just glanced it and left a groove and not be entirely obliterated? Seems to me that given enough time that it would be a possibility.

 

It sure looks like a lake bed or something. It's smoother than the surrounding area so something has gone on there. I doubt that it was a bunch of alien graders so a lake bed seems logical to me.

 

 

But who knows?

[modest]

Is that the same as this?...

 

 

 

which I get from,

 

http://scienceforums.com/topic/14356-pothead-discovers-worlds-largest-impact-crater/page__view__findpost__p__229765

 

I'm not sure if that's a glancing meteor. I think T might have good cause to be skeptical. On the other hand, at least some people have made that same conclusion,

"Occasionally you see craters that are elongated and sometimes you see canyons that have been excavated by incoming meteorites.

 

"You even see lines of multi-ringed craters as if something has bounced over the surface, says Watson.

 

The South Pole-Aitken basin on the Moon is a good example of an elliptical crater. And some scientists argue that a rock the size of Pluto whacked into Mars causing a huge elliptical crater on the planet's north face.

 

http://www.abc.net.au/science/articles/2008/07/10/2299977.htm

 

:unsure:

 

~modest

[Knothead]

Is that the same as this?...

 

 

 

which I get from,

 

http://scienceforums.com/topic/14356-pothead-discovers-worlds-largest-impact-crater/page__view__findpost__p__229765

 

I'm not sure if that's a glancing meteor. I think T might have good cause to be skeptical. On the other hand, at least some people have made that same conclusion,

 

 

http://www.abc.net.au/science/articles/2008/07/10/2299977.htm

 

:unsure:

 

~modest

 

The two photos in your post appear to be the same landmark. But they aren't the same as the one in the OP.

[modest]

The two photos in your post appear to be the same landmark. But they aren't the same as the one in the OP.

 

On second look, yes, I agree.

 

~modest

[Knothead]

One thing that stands out to me is the vertical line(s) that the crater seems to have bisected . In the middle of the image is a line that looks like it was there before the impact.

I have to wonder what the heck that almost straight line was.

I also have to conclude that if it was there before the impact, that there wasn't much debris from the impact. I would think that a impact that destroyed the missile would have obliterated any traces of the line in the immediate vicinity.

[modest]

One thing that stands out to me is the vertical line(s) that the crater seems to have bisected . In the middle of the image is a line that looks like it was there before the impact.

 

Good eye. Yes. :(

 

I have to wonder what the heck that almost straight line was.

 

:unsure: I would feel unqualified to say.

 

I also have to conclude that if it was there before the impact, that there wasn't much debris from the impact. I would think that a impact that destroyed the missile would have obliterated any traces of the line in the immediate vicinity.

 

Oh, I seriously doubt that. If you look at the other features on the photo (in the OP) which are no doubt caused by meteors, there are other meteors nearby which are well-defined. This would mean to me that a meteor impact near another earlier geographic feature wouldn't necessarily destroy the earlier one.

 

~modest

[Turtle]

..."no, there is no foundation for the idea of a 'glancing impact' in the formation of an impact crater". ...

Foundation? I don't know anything about foundations.

 

foundation

2. The basis on which a thing stands, is founded, or is supported.

 

further, you seem to imply by your use of glancing, a deflection as in a richochet or a skip, where the object exits back into space or goes on to impact again as an intact object.

1. Oblique in direction; slanting or deflected 2. Not straightforward; indirect

now granted the dictionary allows glancing as a synonym of oblique, so as long as we're clear that there is no "richochet" or "skip", i allow glancing. i think it's a poor term mind you.

 

 

 

What the heck is the difference between glancing and oblique anyway?

i think i covered that above. in short, it's the difference between subjective & objective.

 

Why couldn't something have just glanced it and left a groove and not be entirely obliterated? Seems to me that given enough time that it would be a possibility.

... not all meteors travel at

the same speed. The slowest travel at 25,000 miles per hour (m.p.h.) and

the fastest at 160,000 m.p.h. ...

source

 

big stuff moving that fast & hitting bigger stuff does not survive. :unsure: speculate all you want, but there is no valid model or calculation extant that proposes or supports richocheting impactors. by all means if you can find one, giver it up for us. :(

[Knothead]

 

big stuff moving that fast & hitting bigger stuff does not survive. :unsure: speculate all you want, but there is no valid model or calculation extant that proposes or supports richocheting impactors. by all means if you can find one, giver it up for us. :(

That's all I'm doing. Speculating. I sure as hell don't know anything and I'll be the first to admit it. But why couldn't something big strike a glancing blow and all of the stuff created by it's impact be shot back out into space or at least somewhere on Mars far away from the initial glancing blow?

I'm not suggesting that the missile would survive. I imagine that it would be pulverized.

[Turtle]

That's all I'm doing. Speculating. I sure as hell don't know anything and I'll be the first to admit it. But why couldn't something big strike a glancing blow and all of the stuff created by it's impact be shot back out into space or at least somewhere on Mars far away from the initial glancing blow?I'm not suggesting that the missile would survive. I imagine that it would be pulverized.

 

because of the laws of physics is why most of the material remains on the impacted planet. at the velocities i gave for meteoroids in space, an impact is nothing short of a bomb. :) let me say again; bomb! :D as i said, if the energy of the impact is sufficient, then some material may be ejected, but it is a small portion of the initial impactor. we in fact have to date found & verified 34 meteorites on earth that originated on mars. >> martian meteorites

 

i have yet to find an impact calculator for mars, but here is one 4 earth that you can put in differrent meteroid/asteroid sizes, materials, velocities, & angles of decent & get a description of the effects both at the site of impact & at varrying distances away. >> impact calculator

 

no skips, no hops, no ricochets, no time... bombs. :omg: :ebomb: :ebomb: :ebomb:

[hummingbird]

One thing that stands out to me is the vertical line(s) that the crater seems to have bisected . In the middle of the image is a line that looks like it was there before the impact.

I have to wonder what the heck that almost straight line was.

I also have to conclude that if it was there before the impact, that there wasn't much debris from the impact. I would think that a impact that destroyed the missile would have obliterated any traces of the line in the immediate vicinity.

 

:) It looks as if something large hit down hard and solid, and molten rock spilled out in a splatter pattern causing the lines!

[modest]

no skips, no hops, no ricochets

 

I am less sure. The explanation (which I think is standard) for this double moon crater,

 

 

is a kind of 'skipping', I believe.

 

FIGURE 115 [above & below].-Messier (1) and Messier A (2) are a pair of unusual craters in northwestern Mare Fecunditatis. Messier is elliptical and has bright walls and light rays of ejecta extending at right angles to its long axis (approximately 16.5 km). Messier A is a doublet crater having two very long rays or filaments of ejecta extending westward from it. The east part of the doublet has steep, bright walls, whereas the west part is dark and appears mantled... Both Messier and Messier A resemble some small experimental impact craters produced in sand by projectiles following shallow trajectories (4° or less from the horizontal) at velocities of approximately 1.7 km/s. In separate experiments using single projectiles, both elliptical craters with lateral ejecta lobes and doublet craters have been produced. Thus, it can be inferred that these lunar craters were produced by high velocity projectiles following shallow trajectories.

 

http://history.nasa.gov/SP-362/ch5.2.htm

 

~modest

[Turtle]

I am less sure. The explanation (which I think is standard) for this double moon crater,

 

 

is a kind of 'skipping', I believe.

FIGURE 115 [above & below].-Messier (1) and Messier A (2) are a pair of unusual craters in northwestern Mare Fecunditatis. Messier is elliptical and has bright walls and light rays of ejecta extending at right angles to its long axis (approximately 16.5 km). Messier A is a doublet crater having two very long rays or filaments of ejecta extending westward from it. The east part of the doublet has steep, bright walls, whereas the west part is dark and appears mantled... Both Messier and Messier A resemble some small experimental impact craters produced in sand by projectiles following shallow trajectories (4° or less from the horizontal) at velocities of approximately 1.7 km/s. In separate experiments using single projectiles, both elliptical craters with lateral ejecta lobes and doublet craters have been produced. Thus, it can be inferred that these lunar craters were produced by high velocity projectiles following shallow trajectories.

 

 

http://history.nasa.gov/SP-362/ch5.2.htm

 

~modest

 

:omg: e tu brute!? :ebomb: i get nothing of the sort from that quote. moreover, 1.7 km/s is a mere 15% of the velocity at which the slowest meteoroids move. (25 000 mile/hour (mph) = 11.176 kilometer/second) no; i see no time for skipping at these velocities and even if there were a skip, it wouldn't be a short one. :ebomb:

 

the formation you show is easily explained by multiple objects traveling together or perhaps one of those potato shaped jobbers like asteroid luetia. :ebomb:

source

 

:D :)

[modest]

:ebomb: e tu brute!?

 

I know, I know, I'm being ornery :ebomb:

 

:ebomb: i get nothing of the sort from that quote.

 

You mean that it's "skipping". Yeah, I guess it doesn't say that in so many words. Here's another that says 'bouncing':

 

And they're not always circular, says astronomer Fred Watson.

"Occasionally you see craters that are elongated and sometimes you see canyons that have been excavated by incoming meteorites.

"You even see lines of multi-ringed craters as if something has bounced over the surface, says Watson.

 

Are impact craters always circular?

 

It doesn't seem too unreasonable to me, but it's not something I've studied.

 

moreover, 1.7 km/s is a mere 15% of the velocity at which the slowest meteoroids move. (25 000 mile/hour (mph) = 11.176 kilometer/second) no;

 

Yeah. I think the minimum possible velocity with which a meteor can hit a planet is the planet's escape velocity, about 11.2 km/s for earth and 5 km/s for mars. So, yeah, it'd be 15% for earth and 45% for mars. I'm not sure how they 'scale up' their impact experiments, but I would guess that velocity would be scaled with distance so it may be appropriate that the velocity of the projectile is slower than a typical meteor. I'm not sure.

 

i see no time for skipping at these velocities and even if there were a skip, it wouldn't be a short one. :)

 

That had occurred to me as well. The distance between the two impact points is roughly 25 kilometers. At a typical speed the meteor would span that distance in less than 2 seconds. Something, it would seem, other than gravity would be needed to change the missile's trajectory.

 

the formation you show is easily explained by multiple objects traveling together or perhaps one of those potato shaped jobbers like asteroid luetia. :D

 

Perhaps. If they do resemble the ones created in a lab with a single impactor though, then that might be the more natural explanation.

 

~modest