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I've seen on this site: https://eclipse.gsfc.nasa.gov/SEhelp/moonorbit.html a table that gives the true anomaly of the moon at the time of new moon. The difference between the true anomaly at one new moon and the true anomaly at the next one, changes all the time. Some times it's almost 40 degrees, and some times it's only 15 degrees. Since earth and moon are at the same angle at new moon, and earth moves about 29 degrees between each new moon, how can the true anomaly of the moon change so much?

Figure 4-1 Length of lunation for 2008 to 2010

Figure 4-2 Moon's orbit and the synodic month

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    $\begingroup$ Did you look at the equations for true anomaly, which depend on orbital eccentricity and inclination? They seem pretty clear. $\endgroup$ – Carl Witthoft Feb 3 '20 at 12:55
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    $\begingroup$ The true anomaly is measured from the Moon's perigee, not the earth-moon-sun angle. At new moon, you would expect the moon's ecliptic longitude to be similar to the sun's, not its true anomaly. $\endgroup$ – user7073 Feb 3 '20 at 17:19
  • $\begingroup$ I don't see where "Some times it's almost 40 degrees, and some times it's only 15 degrees." can be seen in a table, can you clarify? Thanks! $\endgroup$ – uhoh Feb 3 '20 at 23:25

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