Saturn enters retrograde motion

Dominic Ford, Editor
From the Outer Planets feed


Objects: Saturn

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.

2130 apparition of Saturn

11 Feb 2130 – Saturn enters retrograde motion
20 Apr 2130 – Saturn at opposition
30 Jun 2130 – Saturn ends retrograde motion

Observing Saturn

Saturn enters retrograde motion as its 2130 apparition gets underway, although it has already been visible for some weeks in the pre-dawn sky.

Its celestial coordinates as it enters retrograde motion will be:

Object Right Ascension Declination Constellation Magnitude Angular Size
Saturn 14h03m20s 9°47'S Virgo 0.3 17.7"

The coordinates above are given in J2000.0.

From Jacksonville , it will be visible in the morning sky, becoming accessible around 00:18, when it reaches an altitude of 10° above your eastern horizon. It will then reach its highest point in the sky at 05:04, 49° above your southern horizon. It will be lost to dawn twilight around 06:35, 44° above your south-western horizon.

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.

The sky on 26 Nov 2024

The sky on 26 November 2024
Sunrise
06:59
Sunset
17:25
Twilight ends
18:50
Twilight begins
05:34


Waning Crescent

16%

25 days old

Planets
Rise Culm. Set
Mercury 08:27 13:28 18:28
Venus 10:17 15:18 20:18
Moon 02:52 08:47 14:36
Mars 21:40 04:35 11:31
Jupiter 18:11 01:09 08:07
Saturn 13:17 18:59 00:41
All times shown in EST.

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

11 Feb 2130  –  Saturn enters retrograde motion
20 Apr 2130  –  Saturn at opposition
30 Jun 2130  –  Saturn ends retrograde motion
23 Feb 2131  –  Saturn enters retrograde motion

Image credit

© NASA/Cassini

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