The Nodes of the Moon (also called Lunar Nodes) are the two points in space where the Moon's orbital path around the Earth intersects the Earth's orbital plane around the Sun. In Human Design, both the North Node and South Node are used as two of the 13 planetary activations in the BodyGraph calculation. The Nodes move in a slow retrograde cycle of approximately 18.6 years, changing signs approximately every 18 months. Together, the two Nodes govern the trajectory and environment of the vehicle through life. On the Design (Unconscious) side, the Nodes govern the External Environment — the physical trajectory, the geometry of least resistance, and the specific environmental context in which the vehicle is designed to thrive. On the Personality (Conscious) side, the Nodes govern Perspective and View — the specific slice of reality the mind is designed to perceive and engage with.