Eclipse Calculation

[leoplaw]

I believe the ephemeris produces enough information to do the calculation. What I have figured out so far is the following: For the Lunar eclipses, it comes down to finding how close the full moon is to either of the nodes.

Ephemeris.moon.orbit .meanAscendingNode.apparentLongitude Ephemeris.moon.orbit .meanDescendingNode.apparentLongitude

and comparing it to

Ephemeris.moon.position.apparentGeocentric.longitude

Would this be correct, and if so, is there a function / method (orbs?) to do this? Within how many degrees between the moon and it's nodes does a lunar eclipse occur?

With regards to a solar eclipses

when the new moon is close to one of the nodes and only when the Sun is within about 15 to 18 degrees of a node, (10 to 12 degrees for central eclipses).

Total - Moon is near its closest distance to Earth (i.e., near its perigee)

Annular - Moon is near its farthest distance from Earth (i.e., near its apogee)

Suggestions or references would be greatly welcome.