What Ketu Represents
Ketu is associated with detachment, spiritual insight, tendencies from the past, isolation and liberation (Moksha).
Ketu is the natural karaka of the 12th house.
Signs and Dignity of Ketu
Ketu is one of the two lunar nodes. The nodes are not physical bodies. They are the points where the orbit of the Moon crosses the apparent path of the Sun, and they are always exactly opposite each other. They move backwards through the zodiac. Classical texts do not assign them signs of ownership, and traditions differ on the signs of their exaltation and debilitation.
Ketu Dasha
In the Vimshottari system the Ketu Mahadasha lasts 7 years. Within it, each Antardasha lasts the Mahadasha length multiplied by the years of the Antardasha lord and divided by 120. See Dashas for the full sequence.
Nakshatras Ruled by Ketu
Ketu rules three Nakshatras, spaced nine apart in the sequence.