Mercury is the planet of intelligence, information, communication, speech, business, management, calculation and logical mind.
Rahu and Ketu in astrology are the demons. In Hindu mythology story of churning ocean of milk and story related with our subconscious mind. Rahu and Ketu are lunar nodes which play a very important role in evolving human consciousness. Rahu and Ketu are the confusion, illusion, smoke and split thought of the mind. They are always helping us to evolve consciously. They are always in the axis and they are always 180 degrees apart.
Ketu (South Node) is the body of a serpent without a head. It is our past life experience of life and it is already filled with past life experience. Ketu is a detachment, and have no interest in those things where it is placed in the chart. Ketu is not a physical planet but it is the most influential force in the chart. Rahu/Ketu axis is the main force of karmic desire can be seen in the chart. Ketu shows what we need to let go in this lifetime and have peace with it. .
Rahu (North Node) is the head of the serpent and obsessive force in the chart. Rahu always wants something and is obsessed over something. It is our present life desire that we were born. Rahu is an obsession for those things where it is placed in the chart. Rahu and Ketu axis show what work we need to do in this lifetime.
Rahu placement in the house shows that area of life in which we need to develop mentally and Ketu placement shows the area of life where we withdraw ourselves.
Sign is the psychological environment of the planet. The behavior of the planets depends on the sign of the planet.
Mercury with Rahu (North Node)
Rahu conjunct with Mercury and Rahu: These people are looking for more knowledge, communication skills, speech, and intelligence. Rahu makes them project that they are intelligent but inside they feel a lack of it. They focus on gathering more information, learning new things, hobbies, experiments and try learning new things, and working on improving their skill. These people are interested in learning many languages.This conjunction is good if it occurs in good sign and house in birth chart.
Mercury with Ketu (South Node)
Ketu conjunct with Mercury: These people learn to detach from Mercury things. This conjunction shows that these people have good command over Mercury things in their childhood or in past life. They have good ability naturally in debating. They are good at proving their point of view, they are searching for more information about whatever they like, and they are full information. Mercury with Ketu people are good students and they learn so much that they think they don't have to learn anything more. But they are never satisfied with their knowledge and they doubt their own intellectual ability.
These people learn to let go about learning information and rational minds. They should learn to trust into more psychic, abstract knowledge and should believe in higher divine power. They should use their intuitive power for something good. These people can be geniuses if it conjunct in Gemini or Virgo sign where Mercury in own and exalted sign. They could be Guru and have spiritual knowledge, if this conjunction occurs in Pisces sign. These people have psychic ability, and knowledge of the other world (non physical).
As Rahu is an amplifier and Ketu is an attenuator of energy of the planet with which they are sitting. If Rahu sits with Mercury in the sign of Pisces Rahu will amplify the energy of Pisces sign. And if Rahu sits with Mercury in the sign of Gemini Rahu will amplify the energy of the Gemini sign. Same thing applies with Ketu.
