John Zinni wrote:

"Marshall Dudley" wrote in message
...

I never posted it because there are a few flies in the ointment. First
some planets such as mercury do not rotate.

I would double check my facts here if I were you.

Your are right. I had no idea that I was taught wrong in school about mercury
in the early 60's. But I checked and sure enough the textbooks back then do
not agree with what I find now.

I was also taught the moon is locked in it's rotation with one face toward the
earth at all times. That one I believe still stands.

Marshall

http://seds.lpl.arizona.edu/nineplan...s/mercury.html

Until 1962 it was thought that Mercury's "day" was the same length as its
"year" so as to keep that same face to the Sun
much as the Moon does to the Earth. But this was shown to be false in 1965 by
doppler radar observations. It is now known
that Mercury rotates three times in two of its years. Mercury is the only body
in the solar system known to have an
orbital/rotational resonance with a ratio other than 1:1 (though many have no
resonances at all).