Earth axial precession, called “Earth's 3rd Motion”, is the geo-dynamic process which results in the Sun appearing from Earth at any equinox to move counter-clockwise on the ecliptic through constellations of the zodiac: The Precession of the Equinoxes. Through evolving 21st Century techniques (such as VLBI and astronomy from the Moon), accurately observing the Earth’s rotation / precession may help more precisely determine the apparent arrival of the Sun on the ecliptic in the constellation of Aquarius at the time of the vernal equinox, which is now calculated about 2597 AD using the IAU 1928 / current map. With the approach to J2000.0 / New Millennium from the 1960s / 1970s especially, astrophysics and astrometry scientists have been focusing intensely on Earth Precession rates and expressions. Work on Precession and Rotation of the Earth has accelerated since 1930, when the 88 constellations and their boundaries — fixed by Delporte along strict lines of declination and right ascension as they existed at epoch 1875.0 — finally became ratified and published by the International Astronomical Union (IAU). We will also discuss our efforts to form a Working Group with the focus on Earth Precession, Constellations and Epochs — much of which is to be advanced at the planned Galaxy Forum South America 2020 Bariloche on 8 December at which experts will meld research and ideas for astronomy from the Moon, VLBI, precession and the history of constellations in various cultures.