Introduction: "The Ecliptic"
Geocentrically, the Ecliptic is the apparent plane of the Sun's motion - particularly the cycle of the Sun's declination as it moves northward and southward from the tropical of Capricorn to the tropic of Cancer and back. This is the plane which bodies and points are usually measured on in astrology. Thus bodies are being related to the Sun. However it is possible to measure just as simply against the Moon's orbital plane. However I've never seen this done, or even mentioned.
When the Sun crosses the equator moving northward, this is the exact moment it has crossed from Pisces to Aries. When the Sun reaches maximum northern declinarion and starts south, this is the exact moment which it crosses from Gemini into Cancer. Libra shows the southward crossing of the equator, and Capricorn the southern extreme of declination.
The Moon and other bodies are projected onto this plane - thus we say that Pluto has at a particular moment entered Libra regardless of the fact that it will not cross the equator for many years. We say that the Moon has just entered Cancer regardless of the fact that it reached a maximum declination and started southward 24 hours ago.
In eph3 as elsewhere, this is is "Long" = (solar) ecliptical Longitude
Example - Moon and Sun Long for next 30 days.
http://true-node.com/eph3/?dates=30&interval_days=1¢er=geo&an... Moon's Plane / "Ecliptic" We could easily track a measurement of the Moon with signs & degrees according to its own plane rather than the Sun's - and we could also track the placements of other bodies projected onto the Moon's plane rather than the Sun's.
In eph3, the field "firstEcliptic" will generate positions for all bodies based upon the instantous plane ("ecliptic") of the first body listed. Putting Moon first generates these for the Moon.
Example - Moon and Sun, (solar) Long and firstEcliptic (lunar Long) for the next 30 days
http://true-node.com/eph3/?dates=30&interval_days=1¢er=geo&an... Each Body On Its Own Plane - Interesting Results for Pluto especiallyIn theory, we could measure each planet and asteroid according to its own declination cycle. However only the Sun & Moon follow the smooth sine-wave motion of their declination. Other bodies undergo geocentric retrogradation, and thus their declination cycles have little hiccups. Jupiter will cross the equator moving north, then move south for a few months, then north again, several more times before crossing the equator southward. The ebb and flow of declination generated by retrogradation introduces some ambiguity into the concept of "a body's own ecliptic plane".
If we look at the heliocentric measurements, we lose that ambiguity, since the heliocentric declination of planets and asteroids rises and falls in a smooth manner throughout an orbit. We do gain another kind of ambiguity however since we are no longer dealing with an "equator" which has a direct relationship with geocentric observation and seasons.
Bodies which spend quite a long time more than a few degrees off of the ecliptic, such as Pluto, have a declination cycle which is quite a bit out of synch with what is suggested by the (regular solar) ecliptic position. Pluto's declination cycle is roughly 39 degrees behind its tropical position.
Thus, in 1944-5, when Pluto is ~ 9 Leo, it reaches a maximum northern declination (which we call 0 Cancer when the Sun is doing it).
Here are the (heliocentric for simplicity) regular sign changes, and ownEcliptic sign changes for Pluto
http://true-node.com/eph3/?date=1901&time=0000&dates=150&interval...Pluto has recently entered Capricorn in the regular zodiac, however it continues to head toward a maximum southern declination which it won't reach until 2029.
In terms of a declination cycle it is still in a Scorpio phase until 2013.
1913 Long Can
1922 ownEcliptic Gem
1938 Long Leo
1945 ownEcliptic Can
1957 Long Vir
1962 ownEcliptic Leo
1971 Long Lib
1976 ownEcliptic Vir
1984 Long Sco
1988 ownEcliptic Lib
1995 Long Sag
2000 ownEcliptic Sco
2008 Long Cap
2013 ownEcliptic Sag
2024 Long Aqu
2029 ownEcliptic Cap
Still trying to come up with simple language to describe it. ownEcliptic is rather inelegant - I came up with it in a flurry of programming, just trying to get the code written. The literal definition of ecliptic is the "plane on which eclipses occur" so this could be either the solar plane or the lunar plane. I'm pretty happy describing this in terms of the "(solar) ecliptic" pland and the "lunar ecliptic" (plane). But this isn't a good term for what we're looking at for Pluto for instance. I'll probably change what is in eph3 and also this page to ownPlaneLong or something like that.
This table shows the current arc from the helio (solar) long to the helio own-declination-cycle-derived long. These figures tend to stay pretty close over time.
http://true-node.com/eph3/?date=20090815&time=163337&dates=30&int...
HELIO: Body| nNode| ownEclipticD|------------------------------------------------ Pallas| 23 Vir 16| -162°20| Haumea| 2 Leo 14| -66°19| Makemake| 19 Gem 39| -42°45| Pluto| 20 Can 28| -41°03| Varuna| 7 Can 27| -35°31| Eris| 6 Tau 08| -26°29| Sedna| 24 Leo 23| -25°35| Ceres| 20 Gem 31| -21°38| Vesta| 14 Can 02| -16°44| Juno| 20 Vir 02| -11°28| Mercury| 18 Tau 26| -9°49| Venus| 16 Gem 46| -7°21| Saturn| 23 Can 45| -5°27| Thule| 13 Gem 44| -5°00| Neptune| 11 Leo 52| -3°08| Mars| 19 Tau 38| -3°05| Jupiter| 10 Can 35| -2°58| Uranus| 14 Gem 05| -1°41| Moon| | -0°11| Earth| | 0°00| 1999TD10| 4 Lib 44| 1°36| Quaoar| 9 Lib 07| 4°31| Hygiea| 13 Cap 36| 8°13| Chiron| 29 Lib 27| 10°24| Orcus| 28 Sag 49| 41°11| 1996TL66| 7 Sco 53| 72°29|
Pluto we see as -41 right now, meaning subtract 40 or so degrees from the regular helio position. From this we expect Pluto to cross the equator moving northward at about 11 Taurus, and that's close. The traditional bodies are within a few degrees since their orbits are so close to the ecliptic.
These adjustments are basically related to a combination of the inclination of the orbit combined with the placement of the north node.
Where the nNode is in the northern signs, the adjustment is back some degrees, where in the southern it is forward.
Chiron is in the smaller group of southern nNode, so we add about 10 degrees. In other words when it is about 20 (solar) Pisces, it crosses the ecliptic northward, suggesting zero Aries placement by declination.
While helio Chiron didn't enter (solar) Aries until 1968, it crossed the equator in 1965.
Pallas is rather unique. It crosses the equator northward (zero Aries in solar terms) when it is on the western half of the zodiac. This seen quite clearly in the geocentric as well as the helio. I've always had some trouble relating to the sign of Pallas in charts, trying to figure it out. Maybe this is why?
Eris We've all looked at how Eris is in Aries - and has been for some time. However it still hasn't crossed the equator northward - suggesting a Piscean phase. It doesn't cross the equator northward until 2026.
http://true-node.com/eph3/?date=1801&time=0000&dates=250&interval...1838 ownEcliptic Aqu
1846 Long Pis
1923 ownEcliptic Pis
1924 Long Ari
2026 ownEcliptic Ari
2046 Long Tau
...
Nomenclature / ThoughtsThinking about "lunartropical" as an adjective for coordinates projected onto the lunar plane with zero Aries at northward crossing of equator. (what you get on eph3 with Moon as the first body + geocentric + firstEcliptic)."The lunartropical zodiac".
Probably "autotropical" is better than "ownEcliptic" - the setting in eph3 which calculates each body in its own instantaneous plane / it's own declination-cycle. Still really the clearest use of this in my mind is for the helio version of this with outers. When you try to apply the autotropical method with retrograding geo bodies, the picture is not so compelling. The "plane" wildly circling and you're not really seeing a "cycle."
So, smooth, compelling cycles:
* Moon's autotropical positions (same as lunartropical)
* any/all other geo positions in lunartropical coordinates (projected on moon's plane)
* Pluto, Eris, other outers averaged (= helio) autotropical positions
One nice solution to the question of how to deal with geo outers e.g. Pluto in autotropical. Use the averaged (=helio) to define the plane, but put the geo in relation to that plane - thus will oscillate around it. easy to do in eph3 by putting helio Pluto as the first body, geo Pluto as the 2nd and using firstEcliptic option:
http://true-node.com/eph3/?date=2000&time=00&dates=366&interval_d...*Pluto%2C+G*Pluto&.submit=Submit+Query&pos_sort=&s=firstEcliptic&.cgifields=s
So for instance, on 9/11/2001, Pluto is at the first degree of Scorpio.
(from some correspondence:)These words "tropics, tropical, zodiac" are conventionally defined by reference to the Sun. I'm suggesting it need not always be thus. At a given moment, there are indeed lunar "tropics" - particular lines of latitude which indicate the extremes of declination that the Moon travels to. These are at a maximum when the moon's node is at 0 Ari and minimum at 0 Lib.
I'm following a line of inquiry which basically says: we define the Sun's position in a way which does not rely in any way on the position of the Moon or the plane of the Moon. Why don't we try to do the reverse.
Thus, it is the Moon's plane which is primary here, and the conventional/regular/solar ecliptic is not directly involved. The observation that the Moon might be at say 20 Pisces when moving across equator, and thus we can subtract 10 degrees is basically a short cut. It isn't exact, but it's pretty close.
The method used in true-node.com/eph3 is not based upon this short cut.
Once you get a handle on this new (lunar) plane, you can do a simple coordinate transform to get positions not only of the Moon, but the Sun, ASC, MC planet etc.
Everyone one does with (solar) tropical positions in astrology can be done with the lunar, with usually small but sometimes large differences.
