ascending node
greek: ἀναβιβάζων (anabibazōn, 'the ascending one') · latin: caput Draconis (medieval; 'head of the dragon') · arabic: al-raʾs (الرأس, 'the head') · babylonian: kiṣru (Akkadian, 'knot' — for nodal points generally)
Definition
The ascending node is the point on the ecliptic where the orbital plane of the Moon (or a planet) crosses the ecliptic moving from south to north — that is, where the body's ecliptic latitude shifts from negative to positive. The opposing point is the descending node, where latitude reverses from positive to negative. For the Moon this point is also called the north node, true node, or in Vedic astrology Rahu; the line connecting both nodes is the lunar nodal axis.
In Tradition
Across Babylonian, Hellenistic, and Western practice the ascending node is read as one of the two ecliptic-crossing points that mark eclipse risk: a New or Full Moon within about 17° of either node can produce an eclipse. Rochberg documents the Babylonian mathematical-astronomy distinction by latitude-sign behavior — approaching the ascending node with negative latitude increasing toward zero, then passing it with positive latitude increasing.
In Practice
Astrologers read the natal Moon's nodal axis as a thematic spine: the ascending node (Rahu / north node) points toward growth and unfamiliar terrain, the descending node toward the familiar and the released. Eclipse calculation requires the ascending-node longitude — a Moon within the eclipse limit of the node at New or Full produces a solar or lunar eclipse respectively. Modern ephemerides give two versions: the mean node (smoothed orbital average) and the true node (instantaneous oscillating value); traditional Western practice generally uses the mean node, evolutionary astrology often uses true.
Historical Origin
The ascending and descending nodes are documented in Babylonian lunar theory from the Late Babylonian period — Rochberg references their use in eclipse prediction in the Heavenly Writing corpus. Greek transmission preserves the concept as anabibazon ('the ascending one'); the Arabic tradition names the pair al-ra's wa-l-dhanab ('the head and tail') of the dragon, descending into medieval Latin as caput and cauda Draconis.
Etymology
Origin: Greek / Akkadian. Meaning: From Greek anabibazōn ('the one ascending'), parallel to the Akkadian kiṣru ('knot') concept of nodal crossing points in Babylonian lunar theory..
Further Reading
- Francesca Rochberg, The Heavenly Writing
- Demetra George, Astrology and the Authentic Self
- Steven Forrest, The Book of the Moon