Re: UFO help?
Alan Pickup (alan@wingar.demon.co.uk)
Sat, 17 Apr 1999 11:54:42 +0100
>Monday night April 12th between 23:30 and 23:50 EDT (April 13th 04:30 to
>04:50 UTC) I saw what has been confirmed to me by the OIG as the re-entry
>of Cosmos 673 rocket (1974-066B/7418) beginning in an area of the sky
>approximately 20-25 degrees down to roughly 5-7 degrees off the horizon
>slightly to the north of Auriga. I marked the direction and compassed it
>later at close to 315 degrees NW.
In my final report on this object in my posting "Decay watch: Apr 13", I
managed to include the wrong "final elset" for this. In fact the final
published elset was...
Cosmos 673 r 3.8 2.6 0.0 5.1 v 152 x 137 km
1 07418U 74066B 99103.19691916 .12875040 -99969-6 19007-3 0 9667
2 07418 81.1875 179.4923 0011715 264.8612 96.4247 16.48098688358399
Note that this epoch is close to a northbound equator crossing at 04:44
UTC on the 13th.
Using this elset, Mike McCants' LATLONG program gives the following
track when it passed closest to Neptune Beach...
UTC Height(km) Latitude(N) Longitude(W)
04:49 147 23.5 89.9
04:50 149 27.6 89.3
04:51 150 31.7 88.7
04:52 151 35.7 88.1
04:53 153 39.8 87.3
This is not consistent with a re-entry during that pass. Could the final
elset be appreciably in error? It shows the rocket running 5 seconds
early against a SatEvo evolution through earlier elsets, which implies
it was decaying a little faster than SatEvo predicted. However, to force
the SatEvo evolution to decay during the pass, I would need to increase
the drag by a large factor, with the result that it would have been
running *another* 20 seconds earlier than is implied by the elset. I
think this is most unlikely. I would like to know the basis of OIG's
apparent confirmation of this re-entry.
My own analysis of the decay implied that it occurred at 08:14 UTC on
the 13th, with an uncertainty of +-45 minutes. SpaceCom's analysis was
that re-entry occurred within one hour of 08:37 UTC.
>
>Anyway, as 7418 broke up it appeared to split in two somewhere amidships. I
>can say that I saw the lower half melt-into itself and re-enter, but the
>second half may have been propelled back out.
Re-entering objects often fragment, as do bright meteoritic fireballs
which I believe this was.
>
>Is it possible that this second half re-circulated then joined the first
>fracture at or near the same spot 40 odd hours later, or is there a chance
>that the date of the other observation is incorrect?
It could not possibly have been "propelled back out" and re-circulated
for another 40 hours.
Alan
--
Alan Pickup | COSPAR 2707: 55d53m48.7s N 3d11m51.2s W 156m asl
Edinburgh | Home: alan@wingar.demon.co.uk +44 (0)131 477 9144
Scotland | SatEvo page: http://www.wingar.demon.co.uk/satevo/