Linear Binary Pits

[a1call]

Hi all,

I am very much frustrated by these features.



I have yet to hear a convincing explanation for them.

There are some ideas here and here.

The only natural phenomena I can think of which can produce regular patterns is interfering waves. Change the first wave's phase to 24 and leave the rest of the parameters at default to see a natural binary pattern. However I can't see how it would apply here.
I am very much interested in any brainstorms you may offer.

Thanks in advance for any comments.

[Blob]

Hum,
what feature are you talking about?

Image (569kb, 2048 x 2048)

Where is it?

[a1call]

Hi Blob,

Thelinear features should be visible if you click on the thumbnail above.
I have highlighted some of these features here. Please click on the image to open a larger one.

The original image is referenced on the page.

[hhEb09'1]

At first I wondered "why 'binary'?" but then I see that the linear pattern is broken into groups that have clusters of two pits each

[Blob]

@a1call
tnx

Hum,
interesting.
i don't know what they are,
but i would hazard a guess that they were some sort of fault fracture features that created dykes of softer (than the surrounding rock) rock infill that have been excavated by the wind.

[mugaliens]

I dunno. Reindeer?

[mantiss]

If they are on angled slopes, might be just debris rolling off, the double pitted ones I would expect from an irregularly elongated shape object.

What is the angle/elevation of those areas?

[01101001]

If they are on angled slopes, might be just debris rolling off, the double pitted ones I would expect from an irregularly elongated shape object.

I like that, because of the regularity of the pattern. I hope it's a landscape that gets rendered in stereo so the slope can be gauged. Time will tell.

I did some photo manipulation to compare the repeating cycle, aligning a dozen repetitions one on top of the next. It's just too regular to be something that isn't produced by something relatively small -- be it a rolling rock, or a software-induced, or camera hardware artifact. I can't see how a long fissure or collapse would repeat a pattern like that over a distance.

[a1call]

Thanks for all the replies.

the double pitted ones I would expect from an irregularly elongated shape object.

I like that too. Not because I think it solves the issue, but because it is the best hypothesis I have heard so far. If a long rock has two bumps, one in front of the other it should leave a double pitted track when rolling.
Can't conclude positively with one image but if the dark patches are cavities and not just dark soil, then the binary pattern would seem to start from one edge of a peak and continue over the top of the peak and continue over to the other side.
More images of this area would sure be nice.

[JohnD]

It's a crater chain.
Not the inflammatory poster with the wierd ideas about interplanetary warfare, but the observed effect of the breakup of a cometary object into a chain of fragments, due to tidal effects. If those impact a surface, you get a chain of craters.
See Shoemaker-Levy 9.
Also see this BAUT thread on Travis' Fissure on Dione: http://www.bautforum.com/showthread.php?t=15025
A search here, or on Google will find you lots of other examples.
But beware, especially of Googles first hit: http://www.craterchains.com/ .
That's the said inflammatory poster. make of him what you will, but just treat it as comedy.

John

[Cugel]

I can see some problems with the crater chain theory:

1. It doesn't explain the binary effect.
2. Even with Mars' current thin atmosphere you would expect some spreading effect on the impactors? Or at least some collateral impacts?
3. There are many more linear features in that image, (in different directions). How do you explain that?

Not that I have a better explanation.... but it's still pretty weird.

[JohnD]

Cugel,
Thing is, crater chains are common!
And what's more they are spectacularly regular, even when the craters are diferent sizes.
See the chain on Ganymede:
http://www.thunderbolts.info/tpod/20...0810crater.htm

Or the Davy chain on the Moon:
http://www.daviddarling.info/encyclo...ter_chain.html
Which was thought to be from ejecta from another impact, but now is accepted as from a tidally disrupted body. See: http://www.agu.org/pubs/crossref/1995/94GL02966.shtml

Sometimes they are symmetrical, as the Ganymede chain, which ties in with tidal disruption, which could be compared to stretching the incomer from both ends. So to me, a regular chain that shows a 'binary' pattern does not need a special explanation.

As to a 'spreading effect'. Mars' atmosphere has a pressure of 0.7-0.9 kPa at ground level (compare Earth, 100kPa), which is equivalent to Earth's air pressure at about 35 miles high. Most Earth meteors burn up, these are the tiny ones of course, at about 50 miles high. So what atmosphere to provide a 'spreading effect'?
Anyway, would there be a 'spreading effect', even if the atmosphere was thicker? Such an effect would come from winds, that would effect a chain of relatively small falling objects equally, OR from differing aerodynamic effects due to differently shaped objects in the chain. But such objects are surrounded by a shell of ionised gas, that will approximate a sphere, whatever the shape of the object. So no 'spreading effect'.

And the other linear features - no idea! Have you seen the pics of Phobos?
http://spaceflightnow.com/news/n0411/12phobos/
That has grooves not just 'linear features'! How did they get there???

John

[Cugel]

John,

You're probably right, the 'spreading effect' of the atmosphere now seems unlikely to me too. However, what I don't understand is how a meteor can break up in a perfectly straight line of uniformly sized objects. I would expect more of a cloud of debris of randomly sized objects. If crater chains are common as they seem to be, there must be some sort of process that 'creates' the linearity?

[galacsi]

Best explanation is an irregular rolling rock leaving marks as it roll down the slope. I am not a believer in the crater chain theory because as CUGEL perfectly said "I would expect more of a cloud of debris of randomly sized objects. If crater chains are common as they seem to be, there must be some sort of process that 'creates' the linearity?"

[BigDon]

I'm for either a crater chain ala Shoemaker-levy or a long cave collapse along a fault line.

[JustAFriend]

The biggest problem is that the lower the resolution of a photo, the more things tend to "line up" to your eye.

And your eye and brain are hard-wired to pick out repeating patterns (even to the point of seeing things that are NOT there...)

I'd bet good money that if those same photos were shot with a much higher-resolution camera and/or at a slightly different angle, those eerie patterns wouldn't look so eerie (or you might even see new patterns down toward the limit of resolution...)

[JohnD]

Cugel, Galacsi,
Suggest you go to the JPL page on the Shoemaker-Levy event and read out from there. http://www2.jpl.nasa.gov/sl9/

Also, and this is a discovery for me too, see this page from the Department of Space Studies of the Southwest Research Institute:
http://www.boulder.swri.edu/~bottke/rubble/node7.html

In particular, the paragraph on 'B'=class events, "In many cases, the shed fragments go into orbit around the progenitor, producing binary asteroids. If these binaries were to hit a planet at a later time, they would produce two distinct craters. Bottke and Melosh (1996a,b) and Richardson et al.\ (1998) have shown that tidal disruption can create enough binaries to explain the population of doublet craters seen on the terrestrial planets."

This led me to further pages, such as: http://www.astro.umd.edu/~kwalsh/test_handout.pdf

If you would like to see a simulation:
http://www.astro.umd.edu/featured/FormingAsteroids.html
(use the run/stop button to step through the first part, as it runs very fast, and you can miss the binaries. This page points out that tidal disruption explains more than just crater chains, for example, asteroids with their own satellites.
If you prefer a more strictly mathematical tretament, try:http://www.ap.stmarys.ca/~jhahn/pubs/tidal.pdf

Hope that helps

John

[Cugel]

Cugel, Galacsi,

...

Hope that helps

John

It does! Now I'm 99% sure it is a crater chain.
That 1% is for the sheer length of the feature and for the binary effect, which might actually be a trick of the mind anyway.

Just on a side note: I'm quite convinced that SL-9 would not have created a linear crater chain on Jupiter, at least not anything close to the thing on mars we are discussing here. Those objects are indeed of remarkable similar sizes, but they are clearly not on a perfect linear trail and after breaking up in the atmosphere I doubt if any linearity would remain at all.

[galacsi]

It does! Now I'm 99% sure it is a crater chain.
That 1% is for the sheer length of the feature and for the binary effect, which might actually be a trick of the mind anyway.

Just on a side note: I'm quite convinced that SL-9 would not have created a linear crater chain on Jupiter, at least not anything close to the thing on mars we are discussing here. Those objects are indeed of remarkable similar sizes, but they are clearly not on a perfect linear trail and after breaking up in the atmosphere I doubt if any linearity would remain at all.

Why refusing or doubting that SL-9 is a good example when actually it is known to be an objet broken into pieces by gravity tides and on other hand to be sure the track seen on the Op is a crater chain ?

Oups ! , I am a moron and Cugel is clever !

Anyway it is a great and interesting post johnD.

[Blob]

Hum,
(i represent the 1%)
while crater chains are possible, what is the likelihood that several all occurred in this small area?

Why have we not see them in other areas?

[JohnD]

All,
Resurrecting this thread, thanks to pics from HiRise - "Rolling stones"
See:http://hiroc.lpl.arizona.edu//images...SP_001640_2125

These are certainly due to dislodged rocks rolling down the escarpment. See the image subset (fourth para of description), and note the regular 'crater' markings but that the chains of 'craters' are NOT straight.

John

[a1call]

All,
Resurrecting this thread, thanks to pics from HiRise - "Rolling stones"
See:http://hiroc.lpl.arizona.edu//images...SP_001640_2125

These are certainly due to dislodged rocks rolling down the escarpment. See the image subset (fourth para of description), and note the regular 'crater' markings but that the chains of 'craters' are NOT straight.

John

Thread resurrection warning,
Link is broken. So including archived version:
http://web.archive.org/web/200804301...SP_001640_2125

Also perhaps related is

http://www.esa.int/esaSC/SEMK8FEWF0H_index_0.html

Pit-chains can have a volcanic origin. Lava streaming from a volcano solidifies on the surface, leaving a molten tube of lava running below. *

[JustAFriend]

Don't overthink things (that will always get you into trouble).

Go out to a sandy area with a handfuls of gravel.

Throw the gravel really hard at different angles; you'll see the same thing.

[JohnD]

JaF,
So what are you saying?
John

[KaiYeves]

Tell me I'm not the only one who read the title as "binary BITS".

(You know cramming for a Computer Science 101 test has gone to your head when...)