Lunar nodes in vedic astrology

Rahu and Ketu are two sensitive points of intersection of the Moon orbit with the ecliptic, These points are directly opposite each other and change sign in about 18 months and during span of 18 years they complete one Paraya or one cycle of revolution of the zodiac. Their movement is constantly retrograde, meaning, against the normal direction of movement of planets.

Even though they are not physical planets, yet 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.

In mythology, The Nodes are actually demons, because they are the eclipse points and they even have the power to devour the luminaries: The Sun and The Moon.
Nodes relate to the famous lore of how Rahu, inspite being a Asura tried to drink Amrita; during the Samudra Manthan. Lord Vishnu, alarmed by the luminaries, beheaded Rahu, as he was about to swallow the Amrita. The immortal head is known as Rahu and the headless body is Ketu. Felt betrayed by the luminaries, the nodes abhor them, and devour them causing eclipse (grahan).

Rahu and Ketu are given special status and considered as planets in Indian astrology. They are yet treated as full-fledged planets.

Rahu is known as the dragons head and Ketu the Tail.

Head is forward looking and therefore represents the future, whereas Ketu The tail represents the past.

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.

The position of Rahu represents the qualities to be developed and work to be done during the present Janma and the position of Ketu shows the qualities developed during the past lives and in us indicates attitude that come naturally to the native.

Both the Chhaya grahas have no substance and and are physically nonexistent, yet their influence is manifold. and also thier spiritual effects . Since they have a shadow nature, they influence on the psychological level. Rahu is snake shaped and head part is of a celestial snake. Lord Shiva has a snake around him.

The Myth

The emergence of Rahu and Ketu is depicted in the Puranas. The king of the Paradise, Indra 
 was once riding on his elephant Airavata when he met sage Durvasa who is known for his anger. The sage offered him the garland of fortune. Not knowing the merit of the garland Indra put it on the elephant’s trunk who in turn threw it on the floor.

Enraged by this, the sage cursed that he and his team of demigods lose all their power and fortune. 

There is another story too! Ved Vyasa has narrated the emergence of the nodes Rahu and Ketu in his 'Shrimad Baghavataham'. Once Sukracharya, the Guru of the asuras, the demons did a great penance and was rewrded the 'Sanjeevini Mantra'. He could by this raise the dead to life. Knowing this, the demons wanted to defeat the demigods with the help of their guru. Without heeding to the advice of Sukracharya, they started the battle. Duty bound Sukracharya gave life to all the dead asuras and finally, the asuras won the battle. The demons headed by Bali, gained control of the Universe.

 The demigods suffered innumerable insults and finally appealed to Lord Vishnu to help them, who advised them to do 'Sagar Manthan' to get the 'Amrit'. They could regain their lost strength only if they drank Ambrosia, the nectar of immortality, by churning the Ocean of Milk. Nevertheless, it was a great task, which could be accomplished 

only with the help of the demons. The greedy demons were willing to churn the ocean along with demigods. Their plan was to cheat the other party and have the nectar for themselves. However, the divine plan was otherwise! 

 When the ocean was being churned with the Mandhaara Parvat as the rod and Vasuki, the snake, as the chord, many invaluable things, gods, and goddesses appeared. At the end Dhanvantri rose with the pot of nectar.

The demons at once snatched the pot and began to fight among themselves. Lord Vishnu appeared as an enchanting woman (Mohini Avatar). Overcome by her charm, the demons agreed to her plan that the nectar be first offered to the demigods so that the former could have all the rest. The demigods and the demons were seated on opposite rows and the Elixir of immortality was being served to the demigods first, by the Mohini. 

 A wicked idea struck in the mind of one of the demons, Swarbhanu. He assumed the form of a demigod and stealthily sat in the row of the demigods. This was noticed by the Sun who told this to Moon. Moon reported to Lord Vishnu who got so angry that He cut the demon's head. However, as the demon had already tasted the nectar he did not lose his life. 

 After fervent appeals by Rahu and Ketu (the Head and the Tail of the Dragon) they were offered the status of planets with instructions that they go to the ocean of Cancer, learn all the scriptures before assuming office. The nodes sincerely carried this out. Therefore, the node Rahu always chases the luminaries often trying to swallow them in vain, accompanied by his other part Ketu.

RAHU /The Dragon’s Head : 

Rahu is a head without a body. Rahu is non-luminary. it does not emit any light, it does not reflect light.

Rahu is the illusion, the obsession and indulgence leading to self-destruction.

Rahu does not understand limits, traditions, rules and principles. Its like a black hole that will swallow everything, but never be content.

Rahu represents material desire, but because he is not a physical planet, he operates on the subconscious level.

Rahu is the planet for outer fulfillment and Ketu handles inner conquest. Well placed Rahu will bestow all worldly pleasures but never the inner satisfaction.

Rahu is regarded as the main planetary factor behind insanity, neurosis, neurological disorders, possession by negative entities and other such abnormal debilitation of the mind and nervous system.

Rahu rules electronics, computers and the Internet. It is also an influence on social networking which uses the electronic networks. Mining of petroleum.

Rahu governs all sorts of poisonous chemicals like fertilizers, pesticides, and disinfectants that are in use in the present times.

 Rahu indicates mysterious and difficult to treat diseases of various types. It shows collective health problems like epidemics and plagues, and can cause weakness of the immune system

Rahu signifies the taboo - Black Magic, witchcraft, magicians, occultism, metaphysics, poisons, drug dealers, secret societies, illicit relationships and other unconventional aspects. Rahu affiliates with smoke, air, wind and aeronautics - Aircraft, aviation, pilots and space travel falls under its arena.

'Hidden, Unexpected and Sudden' resonates with Rahu, whether its gains or losses, both are Rahu's feature.

Color	Grey, Black
Orbit time in One Zodiac Sign	One and half year (18 months)
Orbit time of whole Zodiac	18 Years (Average)
Nature	Dirty, Furious and aggressive
Constellations ruled	Adra, Swati, Shatbhisha
Friendly planets	Mercury, Saturn, Venus
Enemy planets	Sun, Moon, Mars
Neutral planets	Jupiter
Mool Trikon	Taurus
Exalted in	Taurus
Debilitated in	Sagittarius
Special features	Delay and hurdles
Metal	Graphite, Lead
Precious Stone	Hassonite (Gomed)
Vimshottari Mahadasha period	18 years
If well placed signifies	Prosperity, wealth, Good position
If adversely placed signifies	Arrogance and jealous nature
Representation	Very old people
Diseases given by Rahu	Fever, Leprosy, Snake bite, paranormal activities, Restlessness

Ketu / The Dragon’s Tail :

Ketu - The Moksha-karaka planet is the other half of the demon, the headless body. The shadow planet is non-luminary. It does not emit any light, it does not reflect light.

Ketu shares few traits with Rahu - inclination for the dark side, the magic, occult, poisons and the mystic; Ketu is all about spiritual liberation - through the dreaded path of pain, continuous failures, torture and frustrations.

It is the planet known for major transformations, and transcendence into higher reality.

Ketu supposedly behaves like Mars, so fire and road accidents falls under its arena.

Ketu represents execution of karmic accumulations both good and bad, spirituality and supernatural forces and events. Ketu signifies the spiritual process of the refinement of materialization to spirit and is considered both malefic and benefic, as it causes sorrow and loss, and yet at the same time turns the individual to God. In other words, it causes material loss in order to force a more spiritual outlook in the person. Ketu is exalted in scorpio(vrischika) rashi and is debilitated in taurus(vrishabha) rashi. It is benefic in dhanu(sagittarius) rashi and malefic in mithun(gemini) rashi.

Ketu is friendly with Mercury, Venus, Saturn and Rahu. Ketu is neutral to Jupiter. His enemies are Mars, Sun and Moon. Ketu is a karaka or indicator of intelligence, wisdom, non-attachment, fantasy, penetrating insight, mental unsoundness, and psychic abilities. Ketu is the lord of three nakshatras or lunar mansions: Ashvini, Magha and Mula. The direction associated with is South Lunar Node, the metal is mica and the colour is smoky, element is earth. The food grain is horse gram.

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 Rahu`s obsession and Ketu`s doubt that allows the soul to learn the lessons of the Nodal house and sign placement.

Ketu creates doubt, disturbance, and willfulness’, a critical and narrow vision in life that leads to conflict and disturbances.

Ketu signifies psychic powers, clairvoyance, intuitions, intrigues and desire for knowledge. Unlike Rahu, Ketu deters worldly powers, as it is a deep thinker with keen interest to unearth the esoteric, or beyond the obvious.
Ketu is  affiliated with Ayurveda, herbs and healing abilities. Ketu signifies undiagnosed diseases and is responsible for several severe ailments that leave a permanent mark - leprosy, cancer, paralysis and joint problems.
Ketu is known for the 'Sting' in its tail - By end of its Dasha, it creates a situation that leaves prominent mark on natives’ life.
Ketu is  affiliated with Owls, scorpions, rodents and serpents theVenamous.

Contrary to Rahu, Ketu is comfortable in Scorpio, the sign of Mars; he is most uncomfortable in the sign of glamorous Venus - Taurus. 

Colour	Smoky
Orbit time in One Zodiac Sign	One and half year
Orbit time of whole Zodiac	18 Years (Average)
Nature	Furious
Constellations ruled	Ashwini, Magha, Mool
Friendly planets	Mercury
Enemy planets	Sun & Moon
Neutral planets	Jupiter
Exalted in	Sagittarius
Debilitated in	Taurus/Gemini
Special features	Moksha
Metal	Mix, Mica
Precious Stone	Cat`s eye (Lahsunia)
Vimshottari Mahadasha period	7 years
If well placed signifies	Spiritual attainment
If adversely placed signifies	Arrogance and jealous nature
Representation	Old people
Diseases given by Rahu	Tension & Restlessness

Many ancient astrologers believe Rahu and Ketu do not own any signs, but some say Rahu owns lordship of Aquarius and Ketu is the lord of Scorpio, according to Parashar, Rahu is exalted in Taurus and Ketu in Scorpio.

Cancer is Mooltrikona and Virgo is own sign of Rahu but for Ketu Gemini is Mooltrikona and Sagitattarius and Pisces are his own signs.

Rahu and Ketu own nakshatras, and hence are assigned appropriate dasha periods in the Vimshottari dasha system. Rahu owns Ardra, Swati and Shatabisha and has 18 years of Vimshottari dasha.

Ketu owns Ashvini, Magha and Moola nakshatras and has 7 years out of 120 years of Vinshottari dasha period. In this way if Tauras is the sign of exaltation for Rahu, the 7th from there  Scorpio is his sign of debilitation.

The lunar nodes change sign in about 18 months and during span of 18 years they complete one Paraya or one cycle of revolution of the zodiac.