About Michael Erlewine
Background
Except at the two moments when the Earth is conjunct
or in opposition to a particular planet, the geocentric
position always differs from the heliocentric position.
The helio position is a kind of midpoint about which the
geocentric position ebbs and flows, at least for those
planets beyond the orbit of the Earth. The same thing is
indicated for the inner planets (Mercury and Venus) by
what is called their points of "greatest elongation"
(geocentrically).
This difference between the helio and geo planet
positions is based upon what we can call here the
maximum phase angle possible between Earth and the
planet in question. Below is a list of the maximum phase
angles (average distance from Sun) for the outer
planets using circular orbits —the fact of a non-circular
orbit produces values that may, at times, be greater
than those listed.