Mars ends retrograde motion

Dominic Ford, Editor
From the Outer Planets feed


Objects: Mars

2065 apparition of Mars

12 Jun 2065 – Mars enters retrograde motion
13 Jul 2065 – Mars at opposition
19 Jul 2065 – Mars at perigee
15 Aug 2065 – 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:

18 May 2065
14.4"
15 Jun 2065
19.4"
13 Jul 2065
23.3"
10 Aug 2065
21.7"
07 Sep 2065
17.3"

Observing Mars

Mars leaves retrograde motion as its 2065 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 19:52 (PST), 18° above your south-eastern horizon, as dusk fades to darkness. It will then reach its highest point in the sky at 22:19, 27° above your southern horizon. It will continue to be observable until around 02:04, 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
04 May 206519h20m30s23°31'S12.4”-0.7
18 May 206519h40m20s23°32'S14.4”-1.1
01 Jun 206519h53m10s23°53'S16.8”-1.5
15 Jun 206519h56m50s24°44'S19.4”-2.0
29 Jun 206519h50m20s26°04'S21.8”-2.4
13 Jul 206519h35m10s27°27'S23.3”-2.7
27 Jul 206519h18m30s28°19'S23.2”-2.5
10 Aug 206519h08m40s28°24'S21.7”-2.2
24 Aug 206519h10m20s27°50'S19.5”-1.9
07 Sep 206519h23m10s26°47'S17.3”-1.5
21 Sep 206519h44m40s25°19'S15.2”-1.2

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

Object Right Ascension Declination Constellation Magnitude Angular Size
Mars 19h08m00s 28°16'S Sagittarius -2.1 21.0"

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

35%

23 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

15 Aug 2065  –  Mars ends retrograde motion
30 Aug 2067  –  Mars enters retrograde motion
26 Sep 2067  –  Mars at perigee
02 Oct 2067  –  Mars at opposition

Image credit

© NASA/Hubble Space Telescope

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