(meteorobs) 2011-06-15 - Georgia Fireabll All Sky Video

[Esko Lyytinen]

I got to know, that this was about 8 seconds.
This really makes a difference and it is very probably a natural fireball !

Esko


> Hi,
>
> I earlier got a full size video directly from Steve Fisher. The length
> of this is a little over 16 seconds, and the fireball is visible
> allready in the beginning and still very brigth in the end, then visible
> probably behind some trees of thin clouds.
> I am not sure if this video is (displays) in real speed. In QuickTime
> Palyer the numbers below show only half this much seconds, but it takes
> this 16+ second to display.
> In that Amsmeteors link the video is even more long, but it is moving by
> about 16 or 17 seconds (stays fixed especially in the end).
>
> I think that (in the camera image) the light that is most close to the
> right side is the Moon and with the help of this I could also identify
> Vega, but not sure of this (either these). Making use of some other
> Santinel camera calibrations, I got this very roughly calibrated (but as
> told, not for sure).
>
> I could not split the .mov video (that I got directly from Steve) into
> individual frames (with the Avidemux program, even thout it is stated to
> be capable to this for .mov videos) but measured the beginning and end.
> IF the lengt is really over 16 seconds, then I think that this may be a
> satellite re-entry.
> Assuming a nearly horizontal flight at 7.5 km/s relative to the ground
> (for this roughly Eastward moving object the Earth rotation makes this a
> little slower than without this), the height would be at about 60 km.
> For a assumed velocity of about 11 km/s (the smallest possible from
> outside Earth), this would be around 87 km.
> And if the slope would be bigger and end height smaller, the beginning
> would be bigger. With a slope of about 10 degrees, the height would be
> from 101 to 70 km.
> ( And for a more low end height, the beginnig would correspondingly be
> even more high.) These heights tend to bee too big for a very slow
> meteoroid.  This might be a real Earth-grazer (going back to space), but
> then would expect it to be of even lot more lenth in time. Considering
> the video only this could continue much longer, but the visual
> observations did not give especially long durations (have not read them
> all yet).
>
> According to this solution it would come from the az-direction of about 235.
>
> In the video this is (strongly) fragmenting near the end (and the
> fragments are left much behind the main body), that would not be so
> probable for a quite high flying meteoroid. My camera calibrations may
> be in error, but think probably not too much for these conclusions. The
> main thing is IF the video speed is real, that is, IF the duration of
> the luminous fligth is more than 16 second.
> IF it is, I would think this probably to be a satellite re-entry(?)
> But probably this big entry would be more widely known allready? I would
> advice the satellite experts to check for the known re-entries.
>
> If Steve Fisher reads, this, can you please tell, what is the real video
> speed? I can contact Steve directly, but have not yet done this.
> ( Have been a bit busy and could not start this study at once, after
> this happened. )
>
> Esko
>
>> Hello,
>>
>> A nice video of the recent Georgia Fireball was captured by Steve
>> Fisher of Ty Ty Georgia.
>>
>> You can view this video and more information here:
>>
>> http://www.amsmeteors.org/2011/06/georgia-fireball-june-15th-2011/
>>
>> Its a very nice video capturing the entire event. The fireball is slow
>> and long.
>>
>> I'm interested to hear what people think about this.
>>
>> Thanks,
>>
>> Mike
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