Phenomenon
Retrograde Motion
A planet apparently moving backwards among the stars.
An illusion caused by Earth overtaking (or being overtaken by) another planet in their respective orbits.
Overview
An illusion caused by Earth overtaking (or being overtaken by) another planet in their respective orbits.
See also
Opposition
When a planet sits opposite the Sun in our sky.
Quadrature
A planet 90° from the Sun in our sky.
Elongation
An inner planet's angular distance from the Sun.
Axial Precession
The slow wobble of a planet's rotation axis.
Planetary Ring
A disc of dust and ice circling a planet.
Ring Gap
A clear lane within a planetary ring.