© NASA/Hubble Space Telescope

Mars ends retrograde motion

Dominic Ford, Editor
From the Outer Planets feed

Objects: Mars
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The sky at

2052 apparition of Mars

22 Sep 2052 – Mars enters retrograde motion
19 Oct 2052 – Mars at perigee
27 Oct 2052 – Mars at opposition
28 Nov 2052 – Mars ends retrograde motion

Mars 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 Mars. Not drawn to scale.

The panels below show the month-by-month change in Mars' apparent size in coming weeks, as it recedes from the Earth:

Mars
01 Sep 2052
16.2"
Mars
29 Sep 2052
19.9"
Mars
27 Oct 2052
21.0"
Mars
24 Nov 2052
17.1"
Mars
22 Dec 2052
12.5"

Observing Mars

Mars leaves retrograde motion as its 2052 apparition comes to an end, although it will remain visible for some weeks in the dusk sky.

As retrograde motion ends, it will be visible in the evening sky, becoming accessible around 16:57 (PST), 29° above your eastern horizon, as dusk fades to darkness. It will then reach its highest point in the sky at 21:02, 67° above your southern horizon. It will continue to be observable until around 02:53, when it sinks below 7° above your western horizon.

Begin typing the name of a town near to you, and then select the town from the list of options which appear below.

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

The table below lists Mars' angular size and brightness at two-week intervals throughout its apparition:

Date Right ascension Declination Angular size Magnitude
18 Aug 205202h15m10s10°01'N14.5”-1.1
01 Sep 205202h33m30s11°33'N16.2”-1.4
15 Sep 205202h43m30s12°29'N18.1”-1.7
29 Sep 205202h42m40s12°45'N19.9”-2.0
13 Oct 205202h30m50s12°26'N21.1”-2.3
27 Oct 205202h12m10s11°43'N21.0”-2.5
10 Nov 205201h54m50s11°06'N19.4”-2.1
24 Nov 205201h45m50s11°05'N17.1”-1.6
08 Dec 205201h47m10s11°47'N14.6”-1.1
22 Dec 205201h57m10s13°07'N12.5”-0.7
05 Jan 205302h14m20s14°53'N10.7”-0.3

As it leaves retrograde motion, its celestial coordinates will be:

Object Right Ascension Declination Constellation Magnitude Angular Size
Mars 01h45m10s 11°12'N Pisces -1.5 16.3"

The coordinates above are given in J2000.0.

The sky on 9 Jan 2026

The sky on 9 January 2026
Sunrise
06:56
Sunset
16:59
Twilight ends
18:28
Twilight begins
05:27

21-day old moon
Waning Gibbous

51%

21 days old

Planets
Rise Culm. Set
Mercury 06:35 11:27 16:19
Venus 07:04 12:01 16:58
Moon 22:58 04:55 10:44
Mars 07:01 11:58 16:54
Jupiter 16:55 00:02 07:09
Saturn 10:30 16:24 22:17
All times shown in PST.

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 Nov 2052  –  Mars ends retrograde motion
08 Nov 2054  –  Mars enters retrograde motion
11 Dec 2054  –  Mars at perigee
17 Dec 2054  –  Mars at opposition

Image credit

© NASA/Hubble Space Telescope

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