Lunar nodes

The lunar nodes are the two points where the Moon's orbit crosses the ecliptic, always exactly opposite each other: the North Node, or Dragon's Head, and the South Node, or Dragon's Tail. They move backward through the zodiac in a cycle of about eighteen and a half years and are linked to eclipses. Modern so-called karmic astrology often reads them as an axis of growth: the South Node for what has been acquired, the North Node for the direction to develop. Indian astrology calls them Rahu and Ketu.