<p>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.</p>

CC BY-SA 4.0
2019-06-22T19:14:54.510Z
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 :)
Michail Michailidis
CC BY-SA 4.0
2019-06-22T19:26:54.357Z
Also blimps and the likes are really slow compared to what i saw.
Michail Michailidis
CC BY-SA 4.0
2019-06-22T19:34:29.713Z
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.
Michael Walsby
CC BY-SA 4.0
2019-06-22T19:00:04.103Z
2019-06-22T19:00:04.103Z
Michael Walsby
<p>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.</p>

<p>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.</p>

<p>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: <a href="http://call4obs.iota-es.de/wp-content/uploads/2011/08/palma_south.gif" rel="nofollow noreferrer">http://call4obs.iota-es.de/wp-content/uploads/2011/08/palma_south.gif</a>
Thanks </p>

CC BY-SA 4.0
2019-06-22T15:07:07.330Z
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.
StephenG - Help Ukraine
CC BY-SA 4.0
2019-06-22T15:32:12.887Z
@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?
Michail Michailidis
CC BY-SA 4.0
2019-06-22T16:14:04.733Z
Maybe one of those high-altitude balloons trying to circumnavigate?
Mike G
CC BY-SA 4.0
2019-06-22T16:24:45.410Z
@MikeG which high-altitude balloons look like solid rocks and go in straight lines? I am reading in Wiki that "Rarely, small asteroids passing close to Earth may be visible to the naked eye for a short time"
Michail Michailidis
CC BY-SA 4.0
2019-06-22T16:45:35.460Z
No asteroid would appear that big or fast. See https://astronomy.stackexchange.com/q/14671
Mike G
CC BY-SA 4.0
2019-06-22T16:52:21.947Z
Aliens. Definitely aliens. You have been blessed.
Mick
CC BY-SA 4.0
2019-06-22T16:52:29.523Z
@MikeG thanks for the link! interesting - that is even more confusing now :/
Michail Michailidis
CC BY-SA 4.0
2019-06-22T16:53:11.463Z
@Mick didn't look to have any life :P
Michail Michailidis
CC BY-SA 4.0
2019-06-22T16:54:09.233Z
I'm voting to close this question as off-topic because it is not about any recognisable astronomical body or phenomenon.
Mick
<identify-this-object><near-earth-object>
dull rock/potato-shaped object seen with naked eye, moving in straight line during night. What could it be and is size and speed estimation possible?
Michail Michailidis
# dull rock/potato-shaped object seen with naked eye, moving in straight line during night. What could it be and is size and speed estimation possible?

(Asked by: username_0 on 2019-06-22)

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

**Tags:** identify-this-object, near-earth-object

> **Comments:**
> **username_1**: 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.  
> **username_0**: @username_1 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?  
> **username_2**: Maybe one of those high-altitude balloons trying to circumnavigate?  
> **username_0**: @username_2 which high-altitude balloons look like solid rocks and go in straight lines? I am reading in Wiki that "Rarely, small asteroids passing close to Earth may be visible to the naked eye for a short time"  
> **username_2**: No asteroid would appear that big or fast. See https://astronomy.stackexchange.com/q/14671  
> **username_3**: Aliens. Definitely aliens. You have been blessed.  
> **username_0**: @username_2 thanks for the link! interesting - that is even more confusing now :/  
> **username_0**: @username_3 didn't look to have any life :P  
> **username_3**: I'm voting to close this question as off-topic because it is not about any recognisable astronomical body or phenomenon.  

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## 1 answers

### Answer by username_4 on 2019-06-22. Score: 2

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.

> **Comments:**
> **username_0**: 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 :)  
> **username_0**: Also blimps and the likes are really slow compared to what i saw.  
> **username_4**: 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.  

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