Astrophysics (index)about


(oscillating motion of orbiting bodies relative to each other)

Libration is relative oscillating motion between two orbiting bodies. A common use of the term is in describing the Moon's rocking motion as viewed from Earth. It is also used for similar situations with other orbiting bodies and disks (e.g., circumstellar disks) and other situations where there is such an oscillation.

The moon, as viewed from a point on Earth shows four kinds of libration:

A study of Enceladus's physical libration has been given as evidence of a disconnection between its surface and much of its mass, implying a global ocean under its ice.

Lagrangian points, are also known as libration points. I imagine this is because some of the points are stable, and an object can sit in a small orbit around the point.


Referenced by:
corotation resonance (CR)
Lagrangian point