Saturn ends retrograde motion

Dominic Ford, Editor
From the Outer Planets feed


Objects: Saturn

Saturn will reach the end of its retrograde motion, ending its westward movement through the constellations and returning to more usual eastward motion instead. This reversal of direction is a phenomenon that all the solar system's outer planets periodically undergo, a few months after they pass 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.

2135 apparition of Saturn

10 Apr 2135 – Saturn enters retrograde motion
20 Jun 2135 – Saturn at opposition
30 Aug 2135 – Saturn ends retrograde motion

Observing Saturn

Saturn leaves retrograde motion as its 2135 apparition comes to an end, although it will remain visible for some weeks in the dusk sky.

Its celestial coordinates as it leaves retrograde motion will be:

Object Right Ascension Declination Constellation Magnitude Angular Size
Saturn 17h31m40s 22°12'S Ophiuchus 0.2 17.1"

The coordinates above are given in J2000.0.

From Fairfield , it will become visible at around 19:56 (EDT), 26° above your southern horizon, as dusk fades to darkness. It will then sink towards the horizon, setting at 00:29.

Over the following weeks, Saturn will reach its highest point in the sky four minutes earlier each night, gradually disappearing into evening twilight.

The sky on 28 Apr 2024

The sky on 28 April 2024
Sunrise
05:52
Sunset
19:46
Twilight ends
21:32
Twilight begins
04:07


Waning Gibbous

78%

20 days old

Planets
Rise Culm. Set
Mercury 05:07 11:26 17:45
Venus 05:35 12:12 18:50
Moon 00:03 04:20 08:37
Mars 04:23 10:20 16:16
Jupiter 06:39 13:48 20:57
Saturn 03:58 09:36 15:14
All times shown in EDT.

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

30 Aug 2135  –  Saturn ends retrograde motion
21 Apr 2136  –  Saturn enters retrograde motion
01 Jul 2136  –  Saturn at opposition
10 Sep 2136  –  Saturn ends retrograde motion

Image credit

© NASA/Cassini

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