Date: Mon, 12 Jun 2006 02:12:46 -0400 (EDT)
Subject: Re: [SHG] Re: Skyhook visibility

Thanks for the calculation.  I also consulted the formula in the Condon
Report (Bantam ed. p. 190;  or on the Web at National Capital Area Skeptics
PDF (or analyzing the algebra).  And I got a magnitude of -2.1 from the CR's
formula which is even less bright than the mag -4.6 you got for a 73-ft (22 m)
balloon at 140 miles (225 km).  I agree that just like Venus it is almost
invisible in the daytime sky.

I am not sure where you got the 73 by 129 ft figures from but I suspect that
if the balloon plastic envelope is 73 ft that the 129 is the total length with
both balloon and cable/package thus the latter is 56 ft long (73 + 56 = 129
ft).

Your 1970 satellite analysis report from North American Rockwell (PDF p. 9),
based on 22,000 observations of satellites including the Echo balloon
satellites, gives the formula:

m = -26.58 - 2.5log[AYF/R^2]

where A is cross-sectional area of the object (pi times radius squared for a
sphere or circular flat plate), Y is the reflectivity (assume 100% for maximum
conceivable even though that is impossible), F is the phase factor depending
on sun-observer-object angle and they give a table of formulas to calculate it
on p. 10 (but the maximum would be 0.21), and R is the slant range to the
object.  Use consistent units throughout for A and R (if meters then don't use
kilometers anywhere else in the formula, if you use feet don't use miles
elsewhere, etc.).  .

The Condon Report formula is:

m = -7.16 - 5logD +5logR,

where D is diameter of object, R is slant range, again use consistent units
for both D and R.

I do know an optical physicist interested in UFO's, indeed the leading
expert, Dr Bruce Maccabee, and I'm "cc-ing" him here if he should have any comments.

Bottom line:  No way the 70-foot Skyhook between Nashville and Columbia could
be seen to the naked eye 140 miles away at Godman Tower or by Mantell and his
wingmen or by various civilians calling in to Kentucky State Police about a
250-300-foot disc traveling W at a "pretty fast clip," which is the report that
triggered the alert at Godman at 1 PM that day (plus others, still being
sorted out).