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GlennLeDrew
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Re: July 17 - High Energy Activity near Maginus A new [Re: Roberto_sp]
      #6016324 - 08/09/13 06:19 PM

I've looked at the images posted, and the animated YouTube sequence, and must admit to some confusion about what I'm supposed to be seeing. My first impression was that of a ghost-like reflection, which the optical train used (afocal through an eyepiece) can certainly introduce.

It was requested/suggested a couple of times in this thread for the interval between frames to be provided. That was my first question, too. (At the very least, the interval between first and last frames is required.) In conjunction with an estimate of the areal extent, one can work out a velocity, and provide some constraints on altitude if the 'plume' is ejecta.

But such data have not been forthcoming. Lack of proper documentation? If so, the value of the observation is lessened.

The images themselves evince *very* significant variation due to atmospheric seeing. This alone has the potential to introduce strange artifacts. Indeed, such is the frame-to-frame difference that one could be forgiven for suspecting that smudging has been performed.

If the experts have the required timing data, it will be interesting to read their conclusions...


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Trblmkr
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Re: July 17 - High Energy Activity near Maginus A new [Re: Roberto_sp]
      #6017823 - 08/10/13 03:34 PM

Recycled metal is getting a good price these days.

Time for for a Field Trip


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azure1961p
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Re: July 17 - High Energy Activity near Maginus A new [Re: Trblmkr]
      #6018382 - 08/10/13 11:54 PM

That about said it all.


P.


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Trblmkr
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Re: July 17 - High Energy Activity near Maginus A new [Re: azure1961p]
      #6018481 - 08/11/13 02:05 AM

Quote:

That about said it all.


P.



Though far from being on a level playing field, big bucks are being spent on ocean salvage around the world. Why would that not be a real prospect?


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steveward53
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Re: July 17 - High Energy Activity near Maginus A new [Re: Trblmkr]
      #6018497 - 08/11/13 02:44 AM

I find it increasingly bizarre that this rubbish has not been kicked back under the bridge from whence it came ... ?

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Trblmkr
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Re: July 17 - High Energy Activity near Maginus A new [Re: steveward53]
      #6018529 - 08/11/13 04:13 AM

Everyone should be environmentally sensitive.

Junk is junk no matter where it is.

If there is an objection to the assumption the pictured item(s) is in fact a refined material worth recovering, that would be a matter of interpretation which, is generally based upon knowledge, experience and the ability to discern objects that are of potential value.

If your opinion is opposed to the stated then so be it, no offense is taken, however any opinions expressed in this forum is just that an opinion.

Either side taken of this subject is irrelevant to the facts since neither side can be proven. It is presented here for discussion purposes and is considered necessary fodder for conversation.

I look forward to a meaningful civil dialogue of this subject in a designated forum.

Thanks for your input!


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Roberto_sp
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Re: July 17 - High Energy Activity near Maginus A *DELETED* new [Re: Trblmkr]
      #6018683 - 08/11/13 09:27 AM

Post deleted by Roberto_sp

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steveward53
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Re: July 17 - High Energy Activity near Maginus A new [Re: Roberto_sp]
      #6018976 - 08/11/13 12:42 PM

Someone lock this nonsense please ...

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Roberto_sp
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Re: July 17 - High Energy Activity near Maginus A *DELETED* new [Re: steveward53]
      #6019416 - 08/11/13 05:48 PM

Post deleted by Roberto_sp

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GlennLeDrew
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Re: July 17 - High Energy Activity near Maginus A new [Re: Roberto_sp]
      #6019433 - 08/11/13 06:02 PM

Where's the OP? Did he submit his images to anyone considered to have some expertise in this area? Any follow-up to report?

One tick against the whole thing is jumping the gun and assuming/ascribing to the ambiguous data a "high energy" event, and interpreting the presence of rock and dust debris. Bad form! Anyone with a passing familiarity with the scientific method does not do this.

But far worse? Failing to provide an interval in time for the event. This seriously impairs the data's usefulness. If data it be.


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THEPLOUGH
ELEVEN Grandchildren; FIVE Ducklings
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Re: July 17 - High Energy Activity near Maginus A new [Re: GlennLeDrew]
      #6019563 - 08/11/13 07:28 PM

Enough is enough... This thread has served its' purpose time for the lock...

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THEPLOUGH
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Re: July 17 - High Energy Activity near Maginus A new [Re: THEPLOUGH]
      #6021406 - 08/12/13 06:48 PM

Well at the request of the OP, I am going to give this one more shot... Be nice...

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steveward53
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Re: July 17 - High Energy Activity near Maginus A new [Re: THEPLOUGH]
      #6021416 - 08/12/13 06:54 PM

Your troll , you entertain him .

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GlennLeDrew
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Re: July 17 - High Energy Activity near Maginus A new [Re: steveward53]
      #6022032 - 08/13/13 12:38 AM

I sincerely want to have some idea of the duration of the event. This will permit at least a rough calculation of velocity, which can be compared to characteristic or expected ejection velocities and dispersal times. If this is not not known, it should be stated.

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Trblmkr
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Re: July 17 - High Energy Activity near Maginus A new [Re: GlennLeDrew]
      #6022122 - 08/13/13 02:17 AM

Quote:

I sincerely want to have some idea of the duration of the event. This will permit at least a rough calculation of velocity, which can be compared to characteristic or expected ejection velocities and dispersal times. If this is not not known, it should be stated.




Sorry about the delay I did actually post that information a few days a go but something happened to it. Anyway here it is again;

The camera was set for a 10 shot burst slow setting which equates to 2 images per second for an ET of 5 seconds total. The exposure time was 1/25 sec, but It can not be stated what the entire duration of the event was. The images leading up to the ones provided were shot on a different setting and while there is variations in the series it is not of the same magnitude as those posted, which leads me to believe the first image I have is probably not at the beginning but near the beginning of the event. I have at least 2 additional images (1 second) showing the continuation of the event as well as several other series showing a procession of something that is difficult to describe.
I did not want to post that information until a cause or opinion was rendered by the professionals who are supporting the review.

In due time I plan to post some of the rest of the images for public review.

Until then any information you may be able to develop from the data provided may help to understand what the physics were that resulted in this effect.

JUST THINKING OUT LOUD HERE;
The primary port of the discharge (Maginus A??) has been measured at 13kM however there appears to be multiple ports particularly in frame 2. As well the density of the material traveling from the discharge area would have to be assumed. The distance any material actually traveled is also unknown but Maginus proper is measured at ~100 miles long depending on whose data is used. Gravitational constant is ~ 1/6 earth, not sure what the absolute pressure is, but suspect it greater than 0 psia.

Just considering the scale of the affect of covering ~50,000 sq mi would seem to indicate there was substantial energy involved.
Consider for a moment; To fill a single pipe that is 9 miles across with enough pressure to blow even vapor/dust 50 miles in 5 seconds or less is considerable even at 0 psia and 1/6 gc. Add in there appears to be solid material presumed be to rocks or surface debris that is also being moved.

I don't know if there is a threshold for scientifically defining something as a "high energy" as it is a generic statement. My definitions of high energy means only that it appeared greater than what would likely be produced by the local environment, IE even a huge rock slide or cave in would not likely produce the same affect as what was captured, though it to has considerable energy related to it.
Another aspect and more inline with an engineering analysis, If it were an intentional mechanical process it would definitely be high energy consumption at least by earth standards to produce an effect like that observed. (You'll have to pardon my engineering background)
Anyways you know what you're doing.
If there is anything else I can assist with let me know.
Thanks for your patients.

Thanks
Mark

Edited by Trblmkr (08/13/13 02:55 AM)


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GlennLeDrew
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Re: July 17 - High Energy Activity near Maginus A new [Re: Trblmkr]
      #6022201 - 08/13/13 04:41 AM

We can apply some first order constraints.

First, the explosive nature of an impact results in a circular expansion as viewed perpendicular to the plane of the surface. It cannot intrinsically be strongly and preferentially skewed in one direction. Even our view angle, where the lunar surface is reasonably well tilted with respect to the line of sight, will not result in a *very* significant asymmetry. The ejecta will present as essentially an elliptical pattern, not too far offset from the point of impact in the direction toward nearest point on the lunar limb.

It is thought that the *majority* of impact debris leaves the crater at less than escape velocity, which on the Moon is 2.4 km/s. Over a period of 5 seconds, the distance traveled is then less than 12 km, for a *maximum* diameter of 24 km. This is 1/8 the diameter of 194 km diameter Maginus.

How does this compare to the image scale of the images, meaning the number of pixels/km? And what is the resolution limit imposed by the apparently significant degree of atmospheric seeing? And does the pattern in the image series show expansion from a point, with little or no net motion across the surface beyond that expected due to our perspective on a tilted, symmetrical, ballistic ejecta pattern.

Some small fraction of ejecta, originating from the impactor itself and the surface in pretty much the immediate vicinity, does exceed escape velocity. If we assume, say, 3 times the escape velocity, the distance traveled in 5 seconds is 36 km, for a diameter of about 72 km, or about 1/4 the crater's 194 km diameter. This is certainly large enough to be resolved unambiguously here. But...

... How well should such ejecta be seen against the sunlit surface? The surface is a 'solid' layer of material, and so the surface brightness, considering the sun's angle, is maximal. The ejecta at any fair distance from the impact is expected to have an optical depth of less than unity. In other words, the projected surface density is lower than the surface, where we see through gaps right down to the surface. Considering for simplicity that the debris albedo is similar to that of the underlying surface, the contribution to scene surface brightness cannot be significant, meaning contrast is quite low.

One might ask about increased debris brightness due to being heated to incandescence. While I don't know about duration until cooling to below red hot, for smaller bits it's probably fairly quick. But again, and in any event, the projected surface density (optical depth) would have to be significant in order to rival the underlying sunlit surface's brightness. And so at any kind of distance from the impact, the contrast should be low.

[The following is a very crude (but hopefully) order of magnitude guess of my own. It could well be far in error.]

In order to generate ejecta which can stand out against a sunlit surface, the volume of material ejected must certainly be very considerable, to the point that the projected surface density might well have to approach unity. This suggests a volume equal to the mean diameter of the bits of debris multiplied by the areal extent. If we assume a mean size of 1mm, and a visible areal extent (against the sunlit surface) whose diameter is 24 km, the volume of the material is some 450,000 cubic meters, or a hemispherical crater 120 meters across. (The real crater, of depth less than the horizontal radius, would be wider.)

This is probably a gross underestimate, for our first order calculation was based on the projected surface density of unity at 12 km radius and assuming a constant density all the way back to the impact site. But we must expect density to fall off exponentially with radius, bearing in mind an *approximately* hemispherical distribution. And so the volume of material excavated could/should be greater than calculated above.

Again, the preceding is a *most crude* guess of my own; please take it as such! I am not a geologist, crater expert or explosives handler.


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David Knisely
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Re: July 17 - High Energy Activity near Maginus A new [Re: GlennLeDrew]
      #6022234 - 08/13/13 05:32 AM

This is all very interesting, but it does not change the question as to whether the images represent an event on the moon or not. There are simply too many variables to come to a firm conclusion that this was a lunar surface event and not something like a mere seeing variation or momentary optical effect induced by something in the optics sending scattered light to the camera. In a few days, Maginus will be in sunlight again. Then, we might know a little more, although for me, I won't be at all surprised if it looks exactly as it has for the past few million years. Clear skies to you.

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star dropModerator
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Re: July 17 - High Energy Activity near Maginus A new [Re: David Knisely]
      #6022620 - 08/13/13 10:48 AM

There also remains the possibility that an impact from a predominantly ice object occurred. Would that not reduce the size of an impact scar and produce a vapor cloud with minimal amounts of surface material?

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Asbytec
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Re: July 17 - High Energy Activity near Maginus A new [Re: star drop]
      #6022785 - 08/13/13 12:23 PM

Now, the discussion is back to interesting.

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David Knisely
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Re: July 17 - High Energy Activity near Maginus A [Re: star drop]
      #6023123 - 08/13/13 02:39 PM

Quote:

There also remains the possibility that an impact from a predominantly ice object occurred. Would that not reduce the size of an impact scar and produce a vapor cloud with minimal amounts of surface material?




At the extreme speeds with which celestial objects move relative to each other, the impact effects would not be all that much different between an icy object and one which was not icy but of similar mass. The kinetic energy of a moving object is (1/2)m*v**2, which is dominated by the velocity term. A plume produced by an impact which was large enough to cover much of Maginus would produce a bright flash at the point of impact as well as pretty good sized crater, whether the object was ice or rock. It would also leave a bright ejecta blanket on the surface that would be easily noticeable. In any case, we are still "getting the cart before the horse" here. There is little (if any) firm indication from these images that anything actually happened on the lunar surface. It is more likely that the apparent diffuse brightening shown in the images was due to something a *lot* closer to the surface of the Earth than the surface of the moon. Again, in a couple of days or so, Maginus will be in sunlight once again, so if it looks the same as it always has, nothing probably happened. Clear skies to you.


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