Moon Orbit Oddities

Reading Bob Berman's column in the December "Astronomy" I found this
very odd passage :-)

"Next, the Moon's orbit changes shape all the time. Around New and Full
Moon, it becomes stretched out and eccentric. At other times of the
month, it's more circular. Moreover, its oval shape keeps changing
direction..."
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"Jonathan Silverlight"
wrote...
in message ...

Reading Bob Berman's column in the December "Astronomy" I found this
very odd passage :-)

"Next, the Moon's orbit changes shape all the time. Around New and Full
Moon, it becomes stretched out and eccentric. At other times of the
month, it's more circular. Moreover, its oval shape keeps changing
direction..."
--
What have they got to hide? Release the ESA Beagle 2 report.
Remove spam and invalid from address to reply.

Fourmilab's site explains it fairly well...

http://www.fourmilab.ch/earthview/moon_ap_per.html

Being a writer, Berman has a tendency to exagerate a bit. In
the above he makes the difference sound substantial. Yes, the
Sun's gravity has its greatest effect on the Moon-orbital
eccentricity at full and new Moons, changing it from its usual
5.49%. Judging from the ratio of the Moon-orbit diameter
to the Earth-Moon distance from the Sun, the change in
eccentricity must be tiny. Most references don't mention it.

The changing of direction is a common trait among elliptical
orbits in our Solar System due to the complex gravitational
pulls the Sun has on the planets and the planets have on each
other... another Berman stretch toward dramatization.

Can't really fault him for it, though, can we?

happy days and...
starry starry nights!

--
Freedom! free to see
All the stars, all the cosmos
For what it really is--
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Indelibly yours,
Paine http://www.painellsworth.net