© NASA/Hubble Space Telescope

Mars ends retrograde motion

Dominic Ford, Editor
From the Outer Planets feed

Objects: Mars
Please wait
Loading 0/4
Click and drag to rotate
Mouse wheel to zoom in/out
Touch with mouse to dismiss
The sky at

2153 apparition of Mars

07 Jan 2153 – Mars enters retrograde motion
16 Feb 2153 – Mars at perigee
16 Feb 2153 – Mars at opposition
29 Mar 2153 – 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
22 Dec 2152
9.8"
Mars
19 Jan 2153
12.3"
Mars
16 Feb 2153
13.8"
Mars
16 Mar 2153
12.3"
Mars
13 Apr 2153
9.8"

Observing Mars

Mars leaves retrograde motion as its 2153 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 19:24 (PST), 55° above your eastern horizon, as dusk fades to darkness. It will then reach its highest point in the sky at 21:41, 74° above your southern horizon. It will continue to be observable until around 03:46, when it sinks below 9° 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
08 Dec 215210h16m50s13°25'N8.7”0.3
22 Dec 215210h30m30s12°35'N9.8”-0.0
05 Jan 215310h36m50s12°31'N11.0”-0.3
19 Jan 215310h34m00s13°19'N12.3”-0.7
02 Feb 215310h21m10s14°57'N13.4”-1.0
16 Feb 215310h01m00s16°55'N13.8”-1.2
02 Mar 215309h40m00s18°28'N13.4”-1.0
16 Mar 215309h25m20s19°08'N12.3”-0.7
30 Mar 215309h20m30s18°55'N11.0”-0.3
13 Apr 215309h25m10s18°00'N9.8”0.0
27 Apr 215309h37m10s16°32'N8.7”0.3

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

Object Right Ascension Declination Constellation Magnitude Angular Size
Mars 09h20m30s 18°58'N Cancer -0.3 11.1"

The coordinates above are given in J2000.0.

The sky on 8 Jan 2026

The sky on 8 January 2026
Sunrise
06:56
Sunset
16:58
Twilight ends
18:27
Twilight begins
05:27

20-day old moon
Waning Gibbous

64%

20 days old

Planets
Rise Culm. Set
Mercury 06:32 11:24 16:16
Venus 07:03 12:00 16:56
Moon 21:58 04:13 10:19
Mars 07:02 11:58 16:54
Jupiter 16:59 00:07 07:14
Saturn 10:34 16:27 22:21
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

29 Mar 2153  –  Mars ends retrograde motion
11 Feb 2155  –  Mars enters retrograde motion
23 Mar 2155  –  Mars at opposition
26 Mar 2155  –  Mars at perigee

Image credit

© NASA/Hubble Space Telescope

Share

South El Monte

Latitude:
Longitude:
Timezone:

34.05°N
118.05°W
PST

Color scheme