Here's another from the same general area: 28.598024°, 18.602098°. Again - I wonder if this small multi-concentric ringed structure is a crater or a dried pond. Heck, maybe even both? Granted, it does have Lichtenberg figures all around, and one can hope they weren't supposedly formed by water (instead of merely channeling it when the odd opportunity avails itself in this part of the Libyan Sahara...)
Lloyd, one item in one of the lists you posted is "Habhab (=Oman ring): Oman, Asia, 19.87, 56.93,..." I know that Google Earth's coordinates can sometimes be a bit off, so since I can't find anything exactly there, but nearby at (according to GE) 19.911758°, 57.001515° there is a multi-ringed structure (smaller circles, center left in the picture below), I'm going to assume they're the same thing. If so, then (zooming out) it looks to me that "Habhab" is part of a larger Anode/Cathode discharge structure, the other pole of which encompasses the "White Oryx Project" to the East. Granted, one has to be careful not to mistake car tracks for structural elements, but nonetheless, the whole general area seems to be part of a double-lobe structure. Even with me marking it in red, you really can't see it in this picture, so please check out the "real thing" (ha!) in your favorite satellite photo-providing software.
Lloyd
Re: Help Us Explain Crater Formation!
* Shelgehr, thanks for the links etc. On the first page of this thread, re Richat, I said as follows.
2. The Aug 12, 2005 TPOD, "Richat Crater Revisited (2)", says re chunks of charged material discharging in Earth's plasmasphere: "The discharges would likely fragment the chunks, and the fragments could impact around the craters. But the craters themselves are clearly from EDM because, among other distinctive features, the crater bottoms show no sign of impact fracturing." * Does this mean there are small craters around the larger ones there in and near Algeria, and the smaller ones may be bolide impacts?
* So I had the impression that that TPOD was suggesting that those small structures in the area of Richat are bolide impacts. But the image you linked to looks electrical to me, because of the concentric rings. But maybe there are others in the area that look like bolide impacts. * There are lots of things on Earth to look at, but I think we should focus on investigating features and data that can definitively indicate either electrical or gravitational origin. And central uplifts seem to be the best candidate so far. Shatter cones and other shock metamorphism I guess would be second. There may be several others as well.
Shelgeyr
Re: Help Us Explain Crater Formation!
Lloyd, I agree that Richat is of electrical origin (meaning that I'm convinced of it, not that I can prove it).
You said:
There are lots of things on Earth to look at, but I think we should focus on investigating features and data that can definitively indicate either electrical or gravitational origin. And central uplifts seem to be the best candidate so far. Shatter cones and other shock metamorphism I guess would be second. There may be several others as well.
I would like to strongly suggest that you add "craters that strongly seem to be part of anode/cathode discharges", i.e. craters that occur within paired geological formations that generally fit this description:
1) One side (or pole) resembles a "sunburst" circular formation, often complete with lines radiating out from a central point, surrounded by an outer edge of triangular (or at least pointed or folded) structures "pointing" away from the central axis. The other side (or pole) will usually be far more circular in nature, almost always composed of concentric rings, even if not concave (doesn't have to be a crater). Between the two sides will be striations - connecting lines, often bowed in the middle. Next to these connecting lines (I would say "below" except there's no "above" or "below" here - I just tend to orient the pictures this way) there is often, but not always, a large triangular structure. I'll post pictures of what I'm talking about later when I have some time.
So to sum up - I suggest that any geological formation that really smacks of being a combination anode/cathode discharge scar should be strongly considered as having an electrical origin (unless it is known to be man-made).
Your thoughts?
seasmith
Re: Help Us Explain Crater Formation!
"craters that strongly seem to be part of anode/cathode discharges"
~ And then there is this HD-high-res image of a 'linear crater', on Mars:
From the thread you linked, and the outside site you linked from that thread (http://hirise.lpl.arizona.edu/dtm/), I see among many wonderful pictures the following, which makes me just itch to know what's off camera to the left at the bottom...
Granted this picture is from Mars, and I suppose I should just be referencing things on Earth, but just for example, the two types of craters in the picture on this page are a fairly good example of what I suspect is a cathode/anode structure: http://hirise.lpl.arizona.edu/ESP_020784_1810. That they're smack in the middle of a much larger rayed crater (click the photo to get the zoomed out version) just emphasizes the point. "Residual charge equalization" is my bet. Probably looked like a miniature solar prominence when it was happening.
kiwi
Re: Help Us Explain Crater Formation!
jeeziz Lloyd .. your a machine!
Ive had a quick look at the references, and have not seen the Messier Twins presented (I bet you have them buried somewhere amongst that life-threateningly huge amount of material) but just mentioning as it was said by another poster about the abscence of eliptical craters .... the Messier craters are sure not the norm, ... and the possible explanatuon below is not proven as far as I know
In the early 1950's, famed American meteorite specialist H. H. H. Nininger advanced the hypothesis that the pair Messier and Messier A (then known as W. H. Pickering) was formed by a relatively small impactor tunneling through the unnamed mare ridge on opposite sides of which they appear to reside (and which he dubbed the Tunnel Ridge). The image (click to see a larger version) is taken from his 1952 article in Sky and Telescope. Nininger believed the projectile had burrowed at a shallow angle into a layer of loosely compacted lunar soil, several thousand feet thick and many miles long (but with a density gravitationally equivalent to pine or cork dust on Earth), ricocheting off a more substantial layer below the apparent surface; entering at Messier and exiting at Messier A and forming a melted tube as it passed between them. Modern photos, of course, show no evidence of connecting tube.
The discovery of a ring of craters at the floor of a much larger crater is probably not a new find or a major news item but in this case it may at the very least resolve the argument over one mechanism being involved,, that mechansm,,EDM, Electric Discharge Machining. The ring of dimples at the floor of this crater is complemented by the remains of the main-crater's floor, amidst the connected bowls, being left unassulted by the machining process.. Add to that the accumulation of material in the form of a donut almost smack dab in the middle of that central mass, making this an impossible feature,,, except through the electrical process. I've added some marking to identify the key features to note. d..z
A shock-wave fractured area around an impact crater on a small moonlet. Just kidding. See the NASA page for their real explanation. http://apod.nasa.gov/apod/ap000322.html
davesmith_au
Re: Help Us Explain Crater Formation!
Thanks for that one GaryN, the "real" explanation is even more bizarre than your "moonlet"...
NASA APOD wrote: Explanation: When a meteorite strikes the Moon, the energy of the impact melts some of the splattering rock, a fraction of which might cool into tiny glass beads. Many of these glass beads were present in lunar soil samples returned to Earth by the Apollo missions. Pictured above is one such glass spherule thatmeasures only a quarter of a millimeter across. This spherule is particularly interestingbecause it has been victim to an even smaller impact. A miniature crater is visible on the upper left, surrounded by a fragmented area caused by the shockwaves of the small impact. By dating many of these impacts, some astronomers estimate that cratering on our Moon increased roughly 500 million years ago and continues even today.
... ...
Osmosis
Re: Help Us Explain Crater Formation!
And the U.S. budget can afford this sort of fantasy?
mharratsc
Re: Help Us Explain Crater Formation!
The size of the 'impact crater' on that glass bead indicates a strike that should've shattered the glass bead if it were a complete solid.
Therefore, it stands to (conventional) reason that the glass bead in question must be more of a 'loose pile of glass bead stuff' rather than a solid glass bead, so that it absorbed the impact of the smaller projectile without shattering it.
o.O
GaryN
Re: Help Us Explain Crater Formation!
Just had this sent to me from a friend, but he doesn't remember where it is from. I can't search images on TB, so maybe if anyone recognises it, they can point me to the appropriate post. If this isn't the perfect example of crater formation, or perhaps an ongoing modification, then I don't know what is. I am seeing a plasma or ionised moon dust being pulled in from the surrounding area, perhaps triggering formation of rim craters now and then, being sucked down towards the center, and probably causing those downward pointing dendritic ridges that we see at the inner top of some craters. The center looks hexagonal. This must have been taken from an orbiter or lander with their UV sensitive high speed film. Maybe NASA was hiding this, isn't it conclusive evidence, if not of crater formation, then at least modification, and the reason for those light or UV flashes seen from Earth sometimes?
...
