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Re: APOD: A Twisted Meteor Trail Over Tenerife (2010 Jun 02)
Posted: Wed Jun 02, 2010 2:27 pm
by Wizardwayne
JLo wrote:Two "meteor trails," both with the same spiral twist, appear in the photo. This would tend to rule out a rotating meteor since they are relatively uncommon; but the 2nd one looks so much like the 1st that it may be an aberration, maybe caused by the lens ... or a hoax. In any case, the distant observatory is blurry; but a closer structure is sharper ... so the camera is not properly focused for distant objects (stars and satellites). The trails appear to display a sort of dampened sine wave with a relatively constant period ... like a "ping" on something with a resonant frequency ... like the tripod holding the camera. The distant star trails tend to lead one to believe that the exposure was taken of something moving slower than a meteor ... perhaps an old man-made, defunct, rotating satellite as it orbits the Earth with sunlight reflecting from it. Why would such an object show a dampened wave instead of a constant-amplitude wave? Maybe because it's trajectory is changing as it accelerates toward the earth to its destruction?
The large image on the left side of the frame is an inset of the actual meteor on the right side of the frame. They are the same object, the left side on is a blowup of the actual meteor.
I agree with camera shake, despite photographer's claim that it didn't happen.
Re: APOD: A Twisted Meteor Trail Over Tenerife (2010 Jun 02)
Posted: Wed Jun 02, 2010 2:39 pm
by Middenrat
You see aircraft contrails similarly twisted after interaction with the wingtip trailing vortex
Re: APOD: A Twisted Meteor Trail Over Tenerife (2010 Jun 02)
Posted: Wed Jun 02, 2010 2:40 pm
by RJN
Two attributes might provide evidence that something bumped the camera. First, assuming the meteor moved left-to-right, the fluctuations in position are dying down. This might be expected were the camera bumped.
Second, the fluctuations all appear to be about a single line. If a meteor were changing its course, why would it keep coming back to the same average line of flight? Other models would have to explain this in some way, but the "bumped camera" model is a natural.
I notice
jrendtel@aip.de has posted above and he is the astrophotographer who took this image (and also the President of the International Meteor Organization to boot!). These questions are directed to him: You said there were no animals nearby. Could you yourself have accidentally bumped the camera? Were there any bats around? Could the camera have "settled" on its stand briefly?
- RJN
Re: APOD: A Twisted Meteor Trail Over Tenerife (2010 Jun 02)
Posted: Wed Jun 02, 2010 3:00 pm
by Tilt
Doppelgänger.
Re: APOD: A Twisted Meteor Trail Over Tenerife (2010 Jun 02)
Posted: Wed Jun 02, 2010 3:04 pm
by Marcopie
Even if we are use to see meteors that "comes down" (in photograph the direction is left-to-right) I think that this meteor could have travelled backwards, right-to-left, coming up from horizon to the zenith. In this case the oscillations might have become wider at the end of the track, due to the braking effect of the atmosphere, and ended when the speed was too low to hyonize the air. I think that a meteor the size of a panel, large but flat, could have produced a track like that.
Even the "waving camera" theory is interesting, but the oscillations of the track appears wider than the elongation of stars...
(p.s.: sorry if my writing is not perfect, I'm Italian...)
Re: APOD: A Twisted Meteor Trail Over Tenerife (2010 Jun 02)
Posted: Wed Jun 02, 2010 3:06 pm
by catshoes
"meteors are candidates for seeding life on Earth...."
Wow! The amount of faith that science requires in thinking this stuff up exceeds exponentially the faith I have. It takes my breath away. If I only had faith the size of a mustard seed....
Re: APOD: A Twisted Meteor Trail Over Tenerife (2010 Jun 02)
Posted: Wed Jun 02, 2010 3:10 pm
by anael747
What are the chances that the "spiral" effect is an illusion and that what we are really seing is a side-on view of the meteor skipping and bouncng on the earth's atmosphere before entering?
Re: APOD: A Twisted Meteor Trail Over Tenerife (2010 Jun 02)
Posted: Wed Jun 02, 2010 3:21 pm
by bystander
catshoes wrote:"meteors are candidates for seeding life on Earth...."
If you are going to quote, get it right.
That is quite a difference. Context is everything.
Re: APOD: A Twisted Meteor Trail Over Tenerife (2010 Jun 02)
Posted: Wed Jun 02, 2010 3:26 pm
by cawhitney
I think JLo has it right: Either camera shake or hoax. In fact, I'd say hoax. In all the thousands of meteers photographed at Harvard, there were no examples like this. Also two twisted meteors in this photo are identical except for length of trail. So it cannot be related to the peculiar body of the meteor. Also how could two come at precisely the same phase of the oscillation and show identical patterns? All in all, I'd say it's a fake.
Re: APOD: A Twisted Meteor Trail Over Tenerife (2010 Jun 02)
Posted: Wed Jun 02, 2010 3:28 pm
by Sir Lawrence
By simply observing the other meteor trail in the lower right of the picture you will see the exact same wiggle pattern reproduced. Obviously the two meteors did not wiggle exactly the same way as they passed into the earth's atmosphere. This would lead one to the conclusion that something bumped the camera: animal, flying bug, etc.
Re: APOD: A Twisted Meteor Trail Over Tenerife (2010 Jun 02)
Posted: Wed Jun 02, 2010 3:32 pm
by ParallaxInhibitor
When I was a kid, my family and I went to the mountains for a camping trip. I swear to this day I saw a clearly spiraling meteor fall, but my perspective wasn't as oblique as this image here. I felt as though the meteor was corkscrewing directly toward me.
Reading these comments above, I noticed that no one's really talked about the rotational axis of the meteor before it hits the atmosphere. It's an assumption that they all fall with no rotation or spin. How would the trajectory change if the meteor's spin axis was perpendicular to the direction of motion versus parallel versus non-existent? Or another way to think of it, does rifling come into play?
As the meteor descends into a thicker and thicker atmosphere, it seems reasonable to me that the spiral would be diminishing toward the Earth rather than expanding due to air pressure. I bring this up because I think I see a faint straight line along the same average path as the brighter portion just before the largest spiral/wobble.
Re: APOD: A Twisted Meteor Trail Over Tenerife (2010 Jun 02)
Posted: Wed Jun 02, 2010 3:33 pm
by pleaseconsider
Have any of you ever thrown a football? Wow, leave it to a bunch of geniuses and skeptics to re-create the wheel. Put a light on the posterior end of football, and photograph a poorly thrown/wobbling spiral, and you will get exactly what you see in the picture. Camera moved by animals? Seriously?
Re: APOD: A Twisted Meteor Trail Over Tenerife (2010 Jun 02)
Posted: Wed Jun 02, 2010 3:34 pm
by Dubarnik
You people know nothing. Nothing, I tell you. This metor was on a direct path to collide with the earth. It was going to cause massive damage. One of the alien races that watches over the earth, and I'm not at liberty to say which, deflected the meteor from its collision course. The photographer snapped the picture at the perfect moment to capture the immediate results of the deflection.
Re: APOD: A Twisted Meteor Trail Over Tenerife (2010 Jun 02)
Posted: Wed Jun 02, 2010 3:55 pm
by jman
Does anyone know the direction of travel (is there any way to tell from the image)? Assuming it's towards the right I vote camera shake.
Re: APOD: A Twisted Meteor Trail Over Tenerife (2010 Jun 02)
Posted: Wed Jun 02, 2010 3:57 pm
by Guest
jman wrote:Does anyone know the direction of travel (is there any way to tell from the image)? Assuming it's towards the right I vote camera shake.
Looking at the picture, I would say left to right.
Re: APOD: A Twisted Meteor Trail Over Tenerife (2010 Jun 02)
Posted: Wed Jun 02, 2010 3:58 pm
by DonAVP
I noticed that there are at least thee images in the picture. If you click on the image it will load in its own window you then can zoom up to 1/1. The largest image is a star field with the milky way and the buildings and ground around the lower bottom and right of the image. On top of this is an image about one quarter the size of the first with the meteor trail in it. It is in the upper left. Notice it is out of focus or blurred (possible from camera movement). The stars don't match specifically the milky way does not cross into the blurry image. The last image is about half the size as the second image and is in the right of the picture. It is blurry as well and could be a duplicate of the second, reduced.
We are guessing on the duration of the image but I would guess it was very short. A second and a half at most. This would mean that only the brightest stars would register. If camera movement was the cause in would have to be high frequency bump. Someone noticed the isolation is trailing off this indicates a ring effect or harmonic frequency response in the camera mount.
I cannot decide if this was a real event or and accident or rigged. Just some thoughts and observations.
Re: APOD: A Twisted Meteor Trail Over Tenerife (2010 Jun 02)
Posted: Wed Jun 02, 2010 4:05 pm
by RichD
I've seen numerous photos of maneuverable reentry vehicles with similar motion ... the Lockheed / Navy Mk. 500 reentry system is a good example ... it had a built in asymmetry that generate significant lift ... to maneuver it would stop spinning and "fly" ... it would then spin back up ... while in spin mode it had a similar cork screw signature ... still got the gee wiz publicity photos here somewhere
Re: APOD: A Twisted Meteor Trail Over Tenerife (2010 Jun 02)
Posted: Wed Jun 02, 2010 4:10 pm
by DonAVP
catshoes wrote:"meteors are candidates for seeding life on Earth...."
Wow! The amount of faith that science requires in thinking this stuff up exceeds exponentially the faith I have. It takes my breath away. If I only had faith the size of a mustard seed....
Well said.
I always note that you have to define life before you go off half cocked in assuming were it came from or how it got started. I have never heard a plausible or implausible definition of life yet. I could offer a number of definitions but this is O.T. Just as the 'candidates' statement was O.T. but is often quickly inserted for editorial purposes.
Re: APOD: A Twisted Meteor Trail Over Tenerife (2010 Jun 02)
Posted: Wed Jun 02, 2010 4:39 pm
by Marcopie
Alternative theory: vibrations inducted by the hurt of the reflex mirror (with coincident passing of the meteor... synchronicity?)
Re: APOD: A Twisted Meteor Trail Over Tenerife (2010 Jun 02)
Posted: Wed Jun 02, 2010 5:12 pm
by Groundling
Hi there;
On zooming in to the highest level, I can see that the track in the upper left is part of an enlargement of the track to the right.
Also, the stars in the enlargement show a definite smear that would be in keeping with the the aberration caused by camera shake.
Groundling
Re: APOD: A Twisted Meteor Trail Over Tenerife (2010 Jun 02)
Posted: Wed Jun 02, 2010 5:27 pm
by Guest
JLo wrote:Two "meteor trails," both with the same spiral twist, appear in the photo.
The second meteor is a blow up inset of the first meteor.
-Christian Petersen
Re: APOD: A Twisted Meteor Trail Over Tenerife (2010 Jun 02)
Posted: Wed Jun 02, 2010 5:34 pm
by chucklingchuck
"Brother Occam" told me that this is an artifact due to camera wobble. (Doesn't it look like a damped oscillation waveform?) Also, the star points aren't exactly crisp are they. All other interesting speculation aside my intuition tells me that a simple mechanical vibration at the proper moment of a fairly short exposure could produce the results we see here.
Re: APOD: A Twisted Meteor Trail Over Tenerife (2010 Jun 02)
Posted: Wed Jun 02, 2010 5:35 pm
by Dave Shaffer
I would like to know the camera+lens combination.
This is clearly a fish-eye lens, and most (all?) of the scattered light around the brighter stars (which has been commented on by earlier posters) is due to lens flare. Note that as you go around the edge of the picture, the flare tends to be tangential to the edge of the image (equivalently, orthogonal to the radial direction back towards the center of the image), with the orientation changing as you go around. Note also the coloration in the flares - due to chromatic abberation of the lens.
Note also, despite the claim that the camera was on a tracking mount, that the star images are elongated - mostly left/right and quite similar THROUGHOUT the image. This is NOT the pattern that mis-aligned tracking would generate, and indicates to me that all is not perfect with the functioning of the camera plus mount.
I lean towards a camera bump explanation.
Re: APOD: A Twisted Meteor Trail Over Tenerife (2010 Jun 02)
Posted: Wed Jun 02, 2010 5:35 pm
by Christian Petersen
Chris Peterson wrote:This image has been widely discussed in the meteoritics community. The consensus (unanimous as far as I've seen) is that the camera got jarred by wind or maybe an animal. The same effect has been seen on other images where that happened.
The background stars show the faint telltale elliptical pattern of camera shake. At first glance they look like wings from each star, but the pattern is elliptical, brighter at top and bottom, weakest at the left of each ellipse. The ellipse is brightest at the right, where the star is located, due to greater exposure as the shake damps out.
-Chris Petersen
Re: APOD: A Twisted Meteor Trail Over Tenerife (2010 Jun 02)
Posted: Wed Jun 02, 2010 5:36 pm
by Dently
After doing just a small bit of college trig, for anything to make that wide of a wave (say 3 arcmin) at, say 70 km high (Draconids height), it would have to be jumping back and forth about 60 meters. For a grain of sand to have that kind of trajectory seems highly unlikely to me. Camera wobble seems much more probable.