The North Node of the Moon is called RAHU in Vedic astrology and the South Node is called KETU. They are called dark or shadow planets, because of the Nodes' association with the phenomena of eclipses.
They have no sign ruler ships, although they are said to favor Mercury and Jupiter's signs according to some authorities, while others claim that Rahu favors the sign of Aquarius and Ketu the sign of Scorpio. Rahu, the North Node of the Moon means to conceal, engulf or hide in Sanskrit.
This Graha is associated with the world of material manifestation and worldly desire. Rahu is associated with the spiritual process of involution, or the engrossing of spirit in materialization. Rahu is a karaka, or indicator, of worldly desire, fame, greed, high intelligence, manipulation, obsessive behavior, foreigners, mass disease, dementia and inertia. The nature of this Graha is Vata, or Airy.
The gemstone associated with Rahu is a honey colored hessonite. Rahu reaches full maturity at age 42. The Puranas describe Rahu as half-bodied, born of a lioness, snakelike, having a huge body and being extraordinarily powerful.
The Skanda Purana says that Rahu is instrumental in strengthening ones power and converting even an enemy into a friend. The effect of snakebite is removed by his grace. The lunar and solar eclipses are attributed to Rahu and Ketu. Rahu and Ketu stay 1 1/2 years in each Graha.