Date: Wed, 7 Mar 2012 17:59:04 -0000
From: "Martin Shough" <parcellular@btinternet.com>
Subject: Aug, 21, 1956; near Hamilton AFB, California (BB): AVCAT
To: "Fran Ridge" <nicap@insightbb.com>


Hi Fran

I said to Tom DeMary that I would send you this exchange in case you think it's worth adding to the directory. Tom now agrees with my arguments ruling out a daylight sighting of Venus in this case.

Martin

Sent: Monday, March 05, 2012 12:36 PM
Subject: Re: [Current Encounters] Aug, 21, 1956; near Hamilton AFB, California (BB): AVCAT

Hi Tom

Yes, I confirm your figures for the position of Venus, very bright at mag -3.7, and it seems to have been near maximum elongation too, so plenty far away from the sun. I agree it is a possiblity. Thanks for the suggestion.

However there are some problems:

1) it was near local noon with the sky maximally bright,

2) and although there was unlimited visibility at the flight level there was "thin cirrus" above them at 35,000ft.

3) the object is said to have had a round shape of very large angular size (dime at arm's length) equivalent to more than twice the diameter of the full moon, and was interpreted as "some sort of balloon"

4) the 20 degree error with the azimuth of the object may be significant because the aircraft flew directly towards the object. The total sighting duration is given as 10 min. The first sighting off the right wing lasted about 1 min, after which the pilot turned to pursue. So they headed straight at it for nearly 9 minutes (less decision and turn time) on a recorded heading of 270 degs.

This heading is repeated multiple times in the report and also confirmed in lat-long coordinate format against question 5) Location of Observers: First sighting 38.10 N, 123.00 W; Last sighting 38.10 N, 123.20 W. At 250 kt or 4.17 nmi/min in (say) 8 min in a climb the plane travels about 30 nautical miles on the ground, and if we say that at 38 deg latitude a longitudinal distance of 1 arcminute = about 0.7 naut mi, then this gives 21 arcmin, very close to the 20 arcmin stated. So everything is consistent. It makes no sense that the pilot pursued Venus attempting to close for 8 minutes on a heading 20 degrees away from Venus.

The only possible rescue is the local magnetic variation, because the headings given will be magnetic headings. I haven't checked this, but I'm 100% certain that the correction for California in the mid-'fifties operates in the wrong direction for our purposes, with magnetic bearings rotated maybe 15 deg or so west of true - so 270 M would equal about 285 T ort something of that sort. In other words the real discrepancy with Venus may be as much as 35 deg.

I think that when added to the difficulty of imagining how Venus could seem so bright - through a cirrus veil scattering noon sunlight - as to appear like a round balloon much larger than the moon, the azimuth discrepancy is probably fatal to the Venus theory.

Do you agree? If so I'll ask Fran to put this on the case directory, so that we have covered the bases.

Thanks again and best wishes
Martin


Venus
Magnitude: -3.7
Distance from Sun: 0.726 AU
Distance from Earth: 0.623 AU
Angular size: 27.17 arcsec
Phase: 0.434
Observed at 12:33:41 Aug 21 1956
RA 6h 56m 22s DEC 19° 4' 13”
Alt 53° 7' 45” Az 249° 18' 39”
Rises 3:06:32 Transits 10:08:17 Sets 17:13:59


Name: Sun
Observed at 12:32:51 Tue Aug 21 1956
RA 10h 3m 18s DEC 11° 56' 1”
Alt 62° 12' 15” Az 157° 32' 0”
Rises 6:30:09 Sets 19:59:52
Summer time
Astronomical dawn: 4:50
Astronomical dusk: 21:39
Dark for 7h 10m


----- Original Message ----- From: "Tom DeMary" <tomd_lists@earthlink.net>
To: "Martin Shough" <parcellular@btinternet.com>
Sent: Sunday, March 04, 2012 8:54 PM
Subject: Re: [Current Encounters] Aug, 21, 1956; near Hamilton AFB, California (BB): AVCAT


Hello Martin,

I have been reading some of the discussions on the Current Encounters list.
At the time and place given, the planet Venus was at 50 degrees altitude and
250 degrees azimuth. The azimuth is 20 degrees off from the 270 degrees azimuth
stated in the report, making it difficult to evaluate with certainty whether
the object seen might have been Venus. It should not have been difficult
to see from 20,000 ft, even during daylight. However uncertain, it seems close
enough to the line of sight to consider as a possibility.

Tom DeMary


-----Original Message-----
From: Martin Shough <parcellular@btinternet.com>
Sent: Dec 14, 2011 12:08 PM
To: currentencounters@currentencounters.net
Subject: Re: [Current Encounters] Aug, 21, 1956; near Hamilton AFB, California (BB): AVCAT

within limits things can be said about this one<

It's a shame there isn't more information given, but we can say
something:

The Joint Messageform says the pilot thought the object "appeared
to" go under the B-47 contrail. The phrase implies a matter of
judgment, some possible uncertainty. Unfortunately there is no
questionnaire or signed statement from the observers to help us
gauge what this means.

Assuming the pilot's impression was correct, we could infer
brackets on the object's altitude. It would be between the
minimun typical height for formation of such a contrail and the
maximum likely altitude of the B-47.

Since we know the B-47 was above the F-89's 20,000ft it was
presumably leaving a jet contrail not an aerodynamic contrail,
and the typical minumum for this is given as about 26,000ft. The
likely max altitude of the B-47 would be the service altitude or
about 33,000ft. So the trail would have been somewhere between
6000ft and 13,000 ft above the F-89.

The initial elevation angle of the object from the F-89 cockpit
was 45 deg. Taking this as indicative we could infer (ht / SIN
45deg) a slant distance from the F-89 in the range 8600 - 18, 600
ft.

The angular size of the object is given as a dime at arm's
length, which assuming 0.7 / 33 inches is about 1.2 deg, implying
a physical diameter 170 - 370 ft.

This is huge. The B-47 was on the same 180 deg heading as the
F-89, which was therefore below and behind it. The B-47 is 107ft
long and 116 ft across the wings, The object would have
completely dwarfed the B-47, being not only in the region of
twice its physical size but also significantly nearer than the
B-47 (below and behind it).

It seems unlikely that this would not have been noted, or that
the position of the object in relation to the B-47 trail would
have been in any doubt. Perhaps the angular size of > twice the
size of the full moon is overestimated? This would be the norm.

The observers said they had thought it might be a "possible
balloon of some sort" and ATIC tried to make that work although
no known weather balloon was in the area. And the high power
climbing pursuit with a total time in sight of ten minutes seems
to rule out a nearby balloon. The obhect was sighted 90 deg to
the right of the F-89 course therefore at 270 due West. The file
says the object itself appeared to be on a heading of 270 deg,
and the pilot turned to pursue on a heading of 270 deg at 250 kt,
apparently for several minutes, but the object appeared to "pull
away and up". Moreover the winds at all reported a;ltiudes from
5 to 45,000 ft were from the SW (200-210 deg) so the 270 deg
heading would be substantially against the wind, making nonsense
of the claim that "size, shape, ascending, westerly course are
characteristics of balloon sighting" and the particular balloon
they came up with - the best they could do, launched 5 hours
earlier from Vernalis, Ca.

The impression given is that the object stayed at about the same
bearing from the F-89 from the first sighting and that they
abandoned the attempt to close and left it there, still visible
as they headed back north. One wonders if the apparent position
below the contrail could have been an illusion? Could it have
been a much larger object moving slowly at much greater distance
and altitude? If so one possible candidate is the Moby Dick
balloons being launched around this era. It was desctibed as
"clear silver" in appearance, which might fit the reflectivity of
polyethylene in sunlight. Note the comment from the Director if
Intelligence, 28th Air Div., regarding a balloon from a possilble
"Air Force demonstration elsewhere".

Perhaps Joel or someone can comment on that possiblity?

Martin Shough