Between years 2009-2011, I was located in Greece, watching the perfectly dark night sky around 21:00-23:00 during summer, when I suddenly noticed a very dull dark-brown object that looked like a solid rock/potato having a perceived size around half the diameter of the moon in the sky, moving in a perfect straight line looking up and perceived as fast (it took 3-4 seconds to disappear in the horizon) - so total exposure if I had seen it from start to end would have been less than 10-12 seconds.

One could barely notice it, it had some texture like a rock but blurry. It had almost no light reflection and it wasn't rotating or anything. It wasn't spherical and it was somewhat elongated along the axis of movement. I was barely able to detect it above me with naked eyes, as it was passing from left to right. I only did when I saw it was hiding a small region of the night sky stars. This way I perceived its irregular shape.

Unfortunately I cannot tell it's actual size or how fast it was going. Is it an object of a kind known to astronomers? I couldn't find any similar video footage or anyone seeing something similar talking in the internet. Could it be a space rock (asteroid?) that missed the earth atmosphere and at the same time be seen with naked eyes? Any estimates on space rock type, size and speed based on the time of sky exposure? Any astronomical id from a database or some guidance on how I could search it? Could it be an asteroid occultation like this one: http://call4obs.iota-es.de/wp-content/uploads/2011/08/palma_south.gif Thanks

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    $\begingroup$ Dark night, dark object moving - probably a cloud lit be whatever light was available from the ground. An asteroid large enough to be half the angular size of the Moon would be enormous - impossibly large for astronomers (and the military and anyone else) to miss. $\endgroup$
    – StephenG
    Jun 22 '19 at 15:07
  • $\begingroup$ @StephenG Thanks! definitely not a cloud - since it was not changing shapes and it took 3-4 seconds to disappear. Looked rock solid - could it be a an asteroid occultation like the one in the link? $\endgroup$ Jun 22 '19 at 15:32
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    $\begingroup$ No asteroid would appear that big or fast. See astronomy.stackexchange.com/q/14671 $\endgroup$
    – Mike G
    Jun 22 '19 at 16:45
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    $\begingroup$ @Mick didn't look to have any life :P $\endgroup$ Jun 22 '19 at 16:53
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    $\begingroup$ I'm voting to close this question as off-topic because it is not about any recognisable astronomical body or phenomenon. $\endgroup$
    – Mick
    Jun 22 '19 at 16:54

Rock-shaped doesn't mean very much, rocks come in all shapes and sizes. It couldn't possibly have been an asteroid. It must have been quite large for you to see it at night, but it is surprising you could see the colour of it at night, when colour vision fades. Large, fast, elongated in the direction of motion - it sounds as though it could have been a dirigible, aided by a tail wind. Dirigibles are airships vaguely similar to a zeppelin. The ones with no rigid skeleton are called blimps. They have come back into fashion for certain tasks in the last 20 years or so; there are some in Europe and in USA and probably other countries too, Russia for example. Whether there are any in Greece, I couldn't say, but one thing I can say is that it is far more likely to have been an airship than an asteroid. One possible reason for its rapid disappearance is that it could have disappeared into or behind a cloud.

  • $\begingroup$ Thanks for the answer - I haven't seen any zeppelins in Greece all these years. The texture was really minimal and a bit blurry - it looked like a potato - definitely not symmetric and changing shapes or rotating. No wind or clouds that night. When it gradually disappeared was because of distance. I could sort of see more of the back side of this elongated blob a second before it disappeared. It is certainly clear that it can't have been an asteroid which at this point suffices as an answer. I will wait if anyone has to add anything and will accept it :) $\endgroup$ Jun 22 '19 at 19:14
  • $\begingroup$ Also blimps and the likes are really slow compared to what i saw. $\endgroup$ Jun 22 '19 at 19:26
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    $\begingroup$ Yes,they are qiute slow,but not as slow as they look, because large objects appear slower than smaller ones moving at the same speed. Nevertheless, compared to aircraft they are slow, which is why I suggested there may have been a tail wind. There are other kinds of balloons too, but they are not elongated and are even slower than dirigibles. $\endgroup$ Jun 22 '19 at 19:34

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