Rahu Mahadasha: 18 Years

Rahu is one of the two lunar nodes, and in the vimshottari cycle it has a mahadasha eighteen years long, the fourth of the cycle, between Mangala and Guru. A mahadasha is the major period of a planet, of constant length; an antardasha is the sub-period that a second planet directs inside it. Rahu's is the first period of life if the natal Moon is in Ardra, Svati or Shatabhisha.

This rank exists only in the vimshottari: another method of periods keeps to the seven planets and the Lagna and gives no period to Rahu or Ketu. Its dignities are given in two versions. Rahu may be exalted in Vrishabha, with Mithuna in moolatrikona and Kumbha as its own sign; it may also have Kanya as its own sign. Its debilitation falls in Vrishchika.

Rahu carries you when it is exalted or in dignity, joined or aspected by benefics, in a benefic sign, or in houses 1, 4, 7, 10, 11 or 3. The mood is one of comfort and support from friends and those in power, ties abroad, a religious impulse, a peaceful home and a new dwelling. In house 8 or 12, associated with a malefic or fallen into debilitation, Rahu makes your situation precarious and disturbs the mind. Three phases then follow one another: an arduous beginning, a pause at home in the middle, an end full of anguish.

Two more points. Like Ketu, Rahu is always retrograde and so unfolds its effects in the reverse order of the drekkanas, the thirds of a sign. It also becomes a yogakaraka when it joins a planet that is one. To read your period, start with the house of your Rahu, its sign and the neighboring planets.

To read about the graha itself, open the Rahu guide.