Phenomenon
Opposition
When a planet sits opposite the Sun in our sky.
An outer planet's best viewing geometry — rises at sunset, transits at midnight, sets at sunrise and is closest to Earth.
Overview
An outer planet's best viewing geometry — rises at sunset, transits at midnight, sets at sunrise and is closest to Earth.
See also
Gegenschein
A faint glow opposite the Sun.
Quadrature
A planet 90° from the Sun in our sky.
Elongation
An inner planet's angular distance from the Sun.
Retrograde Motion
A planet apparently moving backwards among the stars.
Axial Precession
The slow wobble of a planet's rotation axis.
Planetary Ring
A disc of dust and ice circling a planet.