The Nodes, called Ketu and Rahu in Hindu astrology, are points of intersection between the path of the Moon along with the apparent path of the Sun in the sky.
Rahu Mahadasha period is for 18 Years in a Horoscope when it gets active and effects as Antardasha period with all the planets.
They aren’t physical heavenly bodies, but their importance in predictive astrology is well recognized.
It has got a head without a body that is normal. It’s fearful to look at. Its body is amorphous and is that of a serpent. It’s tamasik, dark in complexion and thievish by nature. Its motor vehicle is a lion.
It’s by nature a malefic planet. When it isn’t under the influence of another planet, it acts like Saturn. It climbs the hind part.