» The lunar node, quite abstractly speaking, is the point of intersection of the solar and the lunar orbits. There are, therefore, two nodes in opposite positions in the heavens: an ascending node or lunar north node, and a descending node - the lunar south node. The solar and the lunar orbits are not, in effect, in the same but in different planes, enclosing a certain angle. Thus there arise the two opposite points of intersection. The peculiarity of these two points of intersection is that they do not stand still but slowly move. The plane of the lunar path rotates in relation to the plane of the solar path; so the two nodes move a round. They move around the Zodiac in a contrary direction to the rotation of the planets, i.e., from Aries backward through Pisces, Aquarius, etc. A complete revolution of a lunar node takes place in 18 years and 7 months; after this time, therefore, the node — the ascending node, for example — is once again in the same position in the Zodiac as it was before. The ascending node is, thereby, the mathematical point that (at any given time and again after 18 years and 7 months [= 6,798.383 CD] the lunar orbit rises above the solar orbit, while at the opposite point the descending node sinks below it. «
Willi O. Sucher, 1937.
