Neptune and Eris cycle through the millennia
planetary cycle sidereal Astrology
For the long term cycles the "differences" between heliocentric and geocentric placements isn't as big - yet, the charts look different....
When such major and "outer" forces stand in "alignment" with our ecliptic/path, that has significant changes in the "backdrop" as a consequence - of course, also the "angles" in between, where we stand in such a cycle-development ...
Neptune and Eris do have a very interesting and kind of "sharp" relationship/geometry within their orbits - suggesting that their "backdrop" isn't one that goes "un-noticed"....
Eris talks about reality - she's an "eye opener" by using sometimes truly disturbing situations to reveal the truth about situations but mainly about ourselves... Yet, she also tries to bring us revelations from the past, from the collective past and beyond (in this she works also "for" Sedna).
Neptune is about transcending, gaining clarity, dreams, etc. - yet, he also offers the imagination needed to build "new" - that also means new pathways within as he rules the "waters" which includes "cell water"....
Usually we can't gain access to the teachings or benefits of the outer planets until we have transcended the "veils of Neptune" at least a little bit (a little "crack" is sufficient) - if we're trapped within the 3D matrix realm and therefore ruled by some kind of fears, worries, lack and so on, we usually live the "not so nice" attributes of Neptune and other planets....
When we now talk about them "together" in collaboration, it seems truly as being very deep, very profound and very changing....

An overview of the planets orbits - including some of the minor planets (no asteroids).
You can see the "cutting through" orbit of Eris very well here and that she comes not further "in" than the orbit of Neptune...
(sidereal heliocentric data)
Neptune
SN: 16 Cancer 57 NN: 16 Capricorn 57
most South: Libra and most North: Aries
Perihelion: 21 Pisces 47 Aphelion: 21 Virgo 47
Eris
SN: 11 Libra and NN: 11 Aries
most South: Capricorn - most North: Cancer
Perihelion: 19 Virgo Aphelion: 19 Pisces
note their crosses being in the same signs - just "reversed"...

The data of the currently active cycle:
07.08.1848 conjunction 8°12’0” Aquarius
03.12.2022 330 degrees 29°10’30” Aquarius-Pisces
actually both in the constellation Pisces...
07.12.2037 conjunction 2°27’36” Aries
near the star Torculari of Pisces
