Category:Apsides

This category contains results about Apsides.
Definitions specific to this category can be found in Definitions/Apsides.

Let $A$ be a body in orbit $O$ around another body $B$.

Let $\mathbf r$ be the radius of $O$.

An apsis is a point on $O$ at which:

the rate of change of the length of $\mathbf r$ is zero

and:

the velocity of $A$ is perpendicular to $\mathbf r$.