Historical Origins of the Lunar Mansions in Astrology
Before the ecliptic was divided into the twelve zodiac signs, the ancient Indian astronomers recognized 27 divisions called nakshatras.
The primary usage of the nakshatras is a fundamental difference between Western and Vedic astrology. One must deeply encounter and explore the nakshatras to appreciate the diversity and richness of Vedic astrology.
The Moon takes about 27.3 days to complete its sojourn around the ecliptic. The nakshatras represent the average daily movement of the Moon against the fixed stars. Each daily segment is identified by a small constellation or a single star. Originally the length of each nakshatra varied, but by the time the Surya Siddhanta was written (c. 500 CE), a classical astronomy text, the segments were fixed to a length of 13 degrees 20 minutes of arc.
The Sanskrit term nakshatra translates as “that which does not decay” (na – not and kshatra – destructible). Naksh can also indicate approaching, to worship, to guard or protect. Tra is a suffix implying a tool or instrument. Thus, the nakshatras are themselves a means of worship.
Each nakshatra has a symbol that emphasizes its meaning. Unlike the zodiac or “circle of animals” the nakshatras are symbolized by inanimate objects. Swati is shown as a blade of grass blowing in the wind, Chitra is shown as a pearl and Anuradha is symbolized by a lotus flower. Each nakshatra is governed by a Vedic deity. So we find Ashwini ruled by the Ashwin twins, the physicians of the gods, and Hasta governed by Savitar, the creative force of the Sun.
The Rig Veda is a compilation of hymns to the gods and the first known composition in an Indo-European language. Historians agree that the Rig Veda was originally transmitted through an oral tradition, and that it was written down, or codified, no later than 1500 BCE. Several nakshatras are mentioned by name in the Rig Veda. New academic research by Dr. David Frawley and B.N. Narahari Acher suggests that all of the nakshatras are to be found in the Rig Veda, where they are referenced by their associated deity.
The earliest reference to the complete solar zodiac based on 12 sign divisions is found in Mesopotamia c. 450 BCE, yet the Indian astrologers were using the 27 divisions of the nakshatras far earlier. The original lists of the nakshatras always start with Krittika which is associated with the Pleiades. There has been much speculation about why the nakshatra order would start with what we now consider the third in the list. The earliest Indian star calendars were based on the 27 nakshatras, and some scholars believe that the nakshatra system was developed during the time when the vernal equinox occurred in the asterism of the Pleiades. The period when the Pleiades heliacally rose at the vernal equinox was 2720-1760 BCE.