Mars ends retrograde motion

Dominic Ford, Editor
From the Outer Planets feed


Objects: Mars

2063 apparition of Mars

08 Apr 2063 – Mars enters retrograde motion
14 May 2063 – Mars at opposition
22 May 2063 – Mars at perigee
22 Jun 2063 – 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:

19 Mar 2063
10.9"
16 Apr 2063
14.6"
14 May 2063
17.6"
11 Jun 2063
16.8"
09 Jul 2063
13.8"

Observing Mars

Mars leaves retrograde motion as its 2063 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 20:22 (PST), 35° above your southern horizon, as dusk fades to darkness. It will then reach its highest point in the sky at 21:31, 38° above your southern horizon. It will continue to be observable until around 01:58, when it sinks below 7° above your south-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
05 Mar 206315h30m30s17°28'S9.5”0.1
19 Mar 206315h45m50s18°28'S10.9”-0.3
02 Apr 206315h54m10s19°08'S12.6”-0.7
16 Apr 206315h53m20s19°27'S14.6”-1.2
30 Apr 206315h42m20s19°24'S16.4”-1.6
14 May 206315h23m10s18°57'S17.6”-1.9
28 May 206315h02m40s18°18'S17.7”-1.8
11 Jun 206314h48m30s17°53'S16.8”-1.5
25 Jun 206314h44m40s18°01'S15.3”-1.2
09 Jul 206314h51m30s18°46'S13.8”-0.9
23 Jul 206315h07m10s20°01'S12.5”-0.7

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

Object Right Ascension Declination Constellation Magnitude Angular Size
Mars 14h44m30s 17°56'S Libra -1.3 15.6"

The coordinates above are given in J2000.0.

The sky on 11 Jan 2026

The sky on 11 January 2026
Sunrise
06:56
Sunset
17:01
Twilight ends
18:30
Twilight begins
05:27


Waning Crescent

38%

22 days old

Planets
Rise Culm. Set
Mercury 06:40 11:33 16:26
Venus 07:06 12:04 17:02
Moon 00:54 06:18 11:36
Mars 06:59 11:56 16:53
Jupiter 16:42 23:49 06:57
Saturn 10:23 16:16 22:10
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

22 Jun 2063  –  Mars ends retrograde motion
12 Jun 2065  –  Mars enters retrograde motion
13 Jul 2065  –  Mars at opposition
19 Jul 2065  –  Mars at perigee

Image credit

© NASA/Hubble Space Telescope

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