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NEO or dead pixel ?

  1. Oct 18, 2014 #1
    http://www.huffingtonpost.com/2014/10/16/ufo-flies-across-moon



    I don't know what method is being used to keep the moon in frame,
    but if it's a fixed telephoto lens the black dot "UFO" could be a dead-pixel.

    If the 1 pixel-sized black-dot was a real object orbiting Earth , (rather than an artefact),
    and it takes a over minute to cross the moon it would have to be about a kilometre across ?
     
    Last edited: Oct 18, 2014
  2. jcsd
  3. Oct 18, 2014 #2

    russ_watters

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    I think people are letting their imaginations get the better of them (though I'm not even sure what the claim is!). While the video is kinda interesting, a single pixel sillouetted against the moon could very easily just be a satellite. I get satellites spoiling my astrophotos all the time.

    I don't see where you would get your estimate of it being 1 km across. A single pixel shadow makes it an arbitrarily small size.
     
  4. Oct 18, 2014 #3

    mfb

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    The object looks larger than the smallest details visible on the moon, which would suggest more than one camera pixel was involved.

    An object in low earth orbit crosses the moon (full diameter) in about 3 seconds, 45 seconds would need about 4000km distance or a large eccentricity. Unusual for a satellite. A realistic size of 10m at a distance of 4000km would also require the moon to have a diameter of the order of 30'000 px, otherwise the object would be much smaller than a camera pixel and the pixel would not look so dark.
    Something further away would be faster and therefore not in an orbit. A NEO would certainly be possible, but then it would have to be quite dark (possible) or in the shadow of earth (unlikely, but possible).

    The video could be edited to enhance the contrast, of course, then things look differently.
     
  5. Oct 18, 2014 #4

    Drakkith

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    Looks like a dead pixel to me.
     
  6. Oct 18, 2014 #5
    So a minute speck of something on the sensor blocking a group of pixels, rather than 1 pixel.
    [ I've just noticed there's no atmospheric turbulence on the black-dot UFO : if real it's outline (and value) would fluctuate.
    That it is a constant shape and value is consistent with it being an in-camera artefact ].
    The YouTuber said the video is 1080 pixels, (@1:17-1:20), and that the black dot UFO can take a minute to cross the moon's disk.
    If it was a real object orbiting Earth with an orbital velocity twice that of the moon , ( from Earth the moon appears to travel through it's own diameter in about 2 minutes ), then it would be about 1/3rd the distance from the Earth to the moon , and in the 1-10Km range , if it was real and orbiting Earth.
     
    Last edited: Oct 18, 2014
  7. Oct 19, 2014 #6

    mfb

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    Yes, but that is completely dominated by the rotation of earth. If you watch the motion of the moon in an inertial system (relative to stars for example) this time is significantly longer. The object, if real, has to be significantly faster or closer than the moon - a medium earth orbit would be consistent with the speed.
     
  8. Oct 28, 2014 #7
    I believe in UFO's, but not discovered ones or hoaxes. For such a complex race to be spot by us, on a camera, they would have to be moronic at best or declaring war. Why would they be by the Moon, of which they will have seen thousands? They would already know everything they "need" to know about us through a telescope or common knowledge? The chances of them finding and reaching us in this ridiculously huge, spaced-apart galaxy alone is slim at best IMO, even if life here is by the billions, most won't be complex I'm sure. Studying life seems irrelevant by the time you can go as far as them through the Milky Way. Good News, we don't have to worry about dying or be test subjects for awhile! :p
     
    Last edited: Oct 28, 2014
  9. Oct 28, 2014 #8
  10. Oct 28, 2014 #9
    Last edited: Oct 28, 2014
  11. Oct 31, 2014 #10
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