Mars enters retrograde motion

Dominic Ford, Editor
From the Outer Planets feed


Objects: Mars

2076 apparition of Mars

08 Feb 2076 – Mars enters retrograde motion
19 Mar 2076 – Mars at opposition
22 Mar 2076 – Mars at perigee
29 Apr 2076 – Mars ends retrograde motion

Mars will enter retrograde motion, halting its usual eastward movement through the constellations, and turning to move westwards instead. This reversal of direction is a phenomenon that all the solar system's outer planets periodically undergo, a few months before they reach 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:

23 Jan 2076
9.6"
20 Feb 2076
12.3"
19 Mar 2076
14.2"
16 Apr 2076
13.1"
14 May 2076
10.6"

Observing Mars

Mars enters retrograde motion as its 2076 apparition gets underway, although it has already been visible for some weeks in the pre-dawn sky.

As retrograde motion starts, it will be visible in the morning sky, becoming accessible around 21:56, when it reaches an altitude of 9° above your eastern horizon. It will then reach its highest point in the sky at 03:11, 56° above your southern horizon. It will be lost to dawn twilight around 06:17, 34° above your south-western horizon.

Over the following weeks, Mars will reach its highest point in the sky four minutes earlier each night, gradually becoming visible in the evening sky, as well as the pre-dawn sky, as it approaches opposition.

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

Date Right ascension Declination Angular size Magnitude
09 Jan 207612h14m10s1°26'N8.4”0.4
23 Jan 207612h27m10s0°22'N9.6”0.1
06 Feb 207612h33m20s0°01'N10.9”-0.3
20 Feb 207612h31m00s0°34'N12.3”-0.7
05 Mar 207612h19m10s1°57'N13.6”-1.0
19 Mar 207612h00m20s3°51'N14.2”-1.3
02 Apr 207611h40m30s5°33'N14.0”-1.1
16 Apr 207611h26m10s6°27'N13.1”-0.8
30 Apr 207611h20m50s6°21'N11.8”-0.5
14 May 207611h24m40s5°21'N10.6”-0.2
28 May 207611h35m40s3°39'N9.5”0.1

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

Object Right Ascension Declination Constellation Magnitude Angular Size
Mars 12h33m30s 0°04'N Virgo -0.4 11.1"

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

08 Feb 2076  –  Mars enters retrograde motion
19 Mar 2076  –  Mars at opposition
22 Mar 2076  –  Mars at perigee
29 Apr 2076  –  Mars ends retrograde motion

Image credit

© NASA/Hubble Space Telescope

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