Mars ends retrograde motion

Dominic Ford, Editor
From the Outer Planets feed


Objects: Mars

2202 apparition of Mars

06 Feb 2202 – Mars enters retrograde motion
18 Mar 2202 – Mars at opposition
21 Mar 2202 – Mars at perigee
28 Apr 2202 – 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:

21 Jan 2202
9.5"
18 Feb 2202
12.2"
18 Mar 2202
14.1"
15 Apr 2202
12.9"
13 May 2202
10.4"

Observing Mars

Mars leaves retrograde motion as its 2202 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 19:42 (PST), 53° above your south-eastern horizon, as dusk fades to darkness. It will then reach its highest point in the sky at 21:32, 64° above your southern horizon. It will continue to be observable until around 03:10, when it sinks below 8° above your western horizon.

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
07 Jan 220211h59m40s3°01'N8.4”0.4
21 Jan 220212h12m40s1°58'N9.5”0.1
04 Feb 220212h18m50s1°39'N10.8”-0.3
18 Feb 220212h16m20s2°14'N12.2”-0.7
04 Mar 220212h04m30s3°40'N13.5”-1.0
18 Mar 220211h45m40s5°36'N14.1”-1.3
01 Apr 220211h25m40s7°19'N13.8”-1.1
15 Apr 220211h11m20s8°12'N12.9”-0.8
29 Apr 220211h06m00s8°06'N11.6”-0.5
13 May 220211h09m40s7°06'N10.4”-0.2
27 May 220211h20m50s5°25'N9.3”0.1

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

Object Right Ascension Declination Constellation Magnitude Angular Size
Mars 11h06m00s 8°07'N Leo -0.5 11.7"

The coordinates above are given in J2000.0.

The sky on 6 Jan 2026

The sky on 6 January 2026
Sunrise
06:56
Sunset
16:57
Twilight ends
18:26
Twilight begins
05:26


Waning Gibbous

76%

18 days old

Planets
Rise Culm. Set
Mercury 06:26 11:18 16:10
Venus 07:01 11:57 16:52
Moon 19:50 02:43 09:25
Mars 07:04 11:59 16:55
Jupiter 17:09 00:16 07:23
Saturn 10:42 16:35 22:28
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 Apr 2202  –  Mars ends retrograde motion
17 Mar 2204  –  Mars enters retrograde motion
23 Apr 2204  –  Mars at opposition
30 Apr 2204  –  Mars at perigee

Image credit

© NASA/Hubble Space Telescope

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