Rahu and Ketu are the Lunar Nodes in Vedic Astrology.
Rahu and Ketu - (excerpts from \"The Ascendant - The 108 Planets of Vedic Astrology\")
Rahu and Ketu are the Lunar Nodes in Vedic Astrology. They are Grahas in that they grab and attach us to our karma just like the starry Grahas, yet they do not rule over Rasis like the other starry planets. They are shadows, the eclipse points where the Earthï¿½s orbit around the Sun intersects with the Moonï¿½s orbit around the Earth. Even though they are not physical planets they are perhaps the most influential forces in the chart. It is along the Rahu / Ketu axis that the main forces of karmic desire are seen.
The myth of Rahu and Ketu sheds much light on their function and greater possibility. Shortly after the beginning of time, the Gods and demons were in a terrible war, neither side making any progress. So they decided to join forces and churn the milk ocean to get the pot of amrita (immortal nectar) at the bottom. Once the nectar was extracted then came the job of distributing it. The Gods, not wanting the nectar to fall into the hands of the demons, devised a plan. Lord Vishnu disguised himself as the enchanting and beautiful Mohini to distribute the nectar. The Gods and Demons were seated on two different sides of an aisle as Mohini distributed the nectar to the Gods only. The demons were too enchanted by her beauty to notice she was not giving them the nectar. However one demon, Rahu, noticed what was happening and disguised himself as a God and managed to get a drink of the nectar. As soon as this happened, the Sun and Moon told Lord Vishnu what was happening and Vishnu returned to his form as Vishnu and let fly his sudarshan and chopped Rahu in half, but only after Rahu managed to take a drink of the nectar. Thus he is immortal, but chopped in half. The head is Rahu and the tail is Ketu.
Rahu is a head without a body. Everything he comes into contact with he becomes obsessed with, like a person with a voracious appetite. Rahu represents material desire, but because he is not a physical planet he operates on the subconscious level. He distorts our perceptions and colors the world according to his desires. He tends to obliterate the essence of things, focusing on their material substance. He is our deepest subconscious material desire. Rahu obsesses over the things we need to learn so we can eventually be freed of them. There are certain lessons we can only learn in a physical body, in the physical world. Rahuï¿½s obsessions indicate those things. All human beings are crazy in some way, Rahu shows the area of life where we are unbalanced and obsessed. Rahu keeps us obsessed until we learn detachment from what he is influencing. As such, he represents attachment. Losing our higher Self to the things of this world is the main reason we suffer in life. Rahuï¿½s obsessions bring much suffering as long as we desire experience. Once we desire liberation, Rahu is incredibly spiritual.
Ketu is the other half of the demon, the headless body. Where Rahu obsesses over the things of this world, Ketu seeks to be freed from them. Rahu is material and loses the essence of things in their substance. Ketu perceives the essence of things but is unsatisfied with anything substantive in the world. Whereas Rahu wants to grow and experience new things, Ketu wants to fall back on the familiar and withdraw, creating a fear of stagnation and disgust with the familiar that is often turned inward as self-disgust. Ketu brings doubt and sharp criticism to the areas of life that he sees. Eternally unsatisfied, he only notices what is missing from whatever he is influencing. He presides over the absolute aspect of God. He is strict and exacting and sucks the worldly joy out of all he touches, including the things Rahu is obsessed over through house and sign. It is the push and pull of Rahuï¿½s obsession and Ketuï¿½s doubt that allows the soul to learn the lessons of the Nodal house and sign placement.