Rahu is like Saturn, and Ketu is like Mars

The principle «Shanivat Rahu, Kujavat Ketu»
or Rahu is like Saturn, and Ketu is like Mars

They give the effects of the rulers of the signs they occupy. Joining other planets, the nodes eclipse them, absorb their strength and strive to be like them, while these planets, in their turn, become weak and less productive. Rahu and Ketu act in accordance with their placements in the chart, their conjunctions and their dispositors.

It is best when the lunar nodes are placed in the Upachaya houses, that is, in the 3rd, 6th, 10th and 11th houses.

Sri Govind Swarup Agarwal — «Vedic Astrology»