Re: Moon's synchronization (erratum, short)

[David Bowman <dbowman@tiger.gtc.georgetown.ky.us>]

I noticed a couple of errors in my last (& hopefully final) opus on lunar
tidal effects and synchronization that I ought to correct.

1. When discussing the time dependence of the tidal bulges induced in a
perfectly flexible moon I said:
>  ...    The already much-discussed libratory motions will place a
> slight time dependence with a two week period and a few degrees on the
> orientation of the field gradient.  ...

Besides accidently deleting the word 'amplitude' from between 'few degrees'
and "on the slight", I accidently got the period wrong here.  The tiny
few-degree oscillations of the Earth-induced bulges would have a 4-week
(~27.3 day) period, not a two week period.  The (much smaller) solar-
induced tidal bulges on the moon would have a 2-week (~14.8 day) period.

1.  I accidentally misquoted the exponents for a couple of numbers I got
from Allan Cook's book _The_Motion_of_the_Moon_.  I said:
> Moon's princial moments of inertia actually have the values:
> (I_yy - I_xx)/I_zz = (2.28022 +- 0.001) x 10^(-6) and
> (I_zz - I_xx)/I_yy = (6.31787 +- 0.00132) x 10(-6).
                                                ^^
The exponents for these numbers should be -4 not -6.  (The book had quoted
them with the -6 exponent but it had 3 leading digits to the left of the
decimal pt. in the mantissas.  I accidentally changed the mantissas without
correspondingly changing the exponents.  The numerical value I actually
used in calculating the libratory resonant period was correct, however.

David Bowman
dbowman@gtc.georgetown.ky.us