The sun, the moon, and all the
planets (seem to) move around the earth in a belt that is at most 18
degrees wide. This belt is known as the zodiac (see in Group 35). The middle of the
belt is known as the ecliptic, or the "way of the
sun." The movement of the moon around the earth follows an orbit
that is slightly slanting in relation to the ecliptic. On each of its
revolutions around the earth the moon cuts the ecliptic at two
places. The point where the moon cuts the ecliptic from south to north
is known as the moon's north node or caput draconis, the dragon's
signs for the north node have different forms but are, nevertheless,
similar to one another. These nodes take 18-19 years to move
one full revolution through the zodiac. The 18-year cycles are
important both in astronomy, as they make eclipses possible to
predict, and in human life, as they correspond to the age when
individuals are allowed to marry, manage their own bank accounts,
drive cars, etc.
The sign in the middle of those shown here is the graph for the north node as it was drawn in a Greek natal chart more than 2,000 years ago.
According to astrology in a natal chart is a symbol for gifts and resources made available to the individual without them having been consciously sought. It is also associated with blood relations and sexual contacts that lead to childbirth.