# Angular Momentum

The angular momentum of an object is the rotational version of its momentum, and can refer to the orbital angular momentum of an object as it orbits an Orbital Parent, or the spin angular momentum of an object rotating around its own rotation axis.

Like momentum, angular momentum is represented as a 3D vector in Universe Sandbox. The orbital angular momentum is equal to the cross product of an object's position and its momentum. In other words, the angular momentum has a magnitude of

where *D* is the distance between the object and the reference point of its motion, *M* is the object's mass, *V* is the magnitude of the object's velocity vector, or its speed, and θ is the angle between the object's position vector and momentum vector. The direction of the angular momentum vector will point perpendicularly to both the position and momentum vectors, following the right-hand rule of vector mathematics.

The spin angular momentum of a rotating object, simulated as a solid sphere, is

where *R* is the radius of the object and *V*_{eq} is the linear speed at the equator of the object.