Saturn will enter retrograde motion, halting its usual eastward movement through the constellations, and turning to move westwards instead. This reversal of direction is a phenomenon that all the solar system's outer planets periodically undergo, a few months before they reach opposition.
The retrograde motion is caused by the Earth's own motion around the Sun. As the Earth circles the Sun, our perspective changes, and this causes the apparent positions of objects to move from side-to-side in the sky with a one-year period. This nodding motion is super-imposed on the planet's long-term eastward motion through the constellations.
The diagram below illustrates this. The grey dashed arrow shows the Earth's sight-line to the planet, and the diagram on the right shows the planet's apparently movement across the sky as seen from the Earth:
The retrograde motion of a planet in the outer solar system.
Not drawn to scale.
Observing Saturn
Saturn enters retrograde motion as its 2166 apparition gets underway, although it has already been visible for some weeks in the pre-dawn sky.
As retrograde motion starts, it will be visible in the dawn sky, rising at 00:41 (PST) and reaching an altitude of 34° above the southern horizon before fading from view as dawn breaks at around 05:29.
Over the following weeks, Saturn will reach its highest point in the sky four minutes earlier each night, gradually becoming visible in the evening sky, as well as the pre-dawn sky, as it approaches opposition.
As it begins retrograde motion, its celestial coordinates will be:
| Object | Right Ascension | Declination | Constellation | Magnitude | Angular Size |
| Saturn | 19h16m20s | 21°47'S | Sagittarius | 0.2 | 17.2" |
The coordinates above are given in J2000.0.
The sky on 15 Dec 2025
| The sky on 15 December 2025 | ||||||||||||||||||||||||||||||||||
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12% 26 days old |
All times shown in PST.
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Source
The circumstances of this event were computed using the DE430 planetary ephemeris published by the Jet Propulsion Laboratory (JPL).
This event was automatically generated by searching the ephemeris for planetary alignments which are of interest to amateur astronomers, and the text above was generated based on an estimate of your location.
Related news
| 28 Apr 2166 | – Saturn enters retrograde motion |
| 08 Jul 2166 | – Saturn at opposition |
| 17 Sep 2166 | – Saturn ends retrograde motion |
| 10 May 2167 | – Saturn enters retrograde motion |
Image credit
© NASA/Cassini