© 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

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.

2103–2104 apparition of Mars

10 Dec 2103 – Mars enters retrograde motion
16 Jan 2104 – Mars at perigee
19 Jan 2104 – Mars at opposition
28 Feb 2104 – Mars ends retrograde motion

Observing Mars

Mars leaves retrograde motion as its 2103–2104 apparition comes to an end, although it will remain visible for some weeks in the dusk sky.

Its celestial coordinates as it leaves retrograde motion will be:

Object Right Ascension Declination Constellation Magnitude Angular Size
Mars 07h22m10s 25°49'N Gemini -0.4 11.3"

The coordinates above are given in J2000.0.

From Ashburn , it will be visible in the evening sky, becoming accessible around 18:16 (EDT), 53° above your eastern horizon, as dusk fades to darkness. It will then reach its highest point in the sky at 21:00, 76° above your southern horizon. It will continue to be observable until around 03:37, when it sinks below 9° above your north-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 panels below show the month-by-month change in Mars' apparent size in coming weeks, as it recedes from the Earth:

Mars
03 Jan 2104
Mars
31 Jan 2104
Mars
28 Feb 2104
Mars
27 Mar 2104
Mars
24 Apr 2104

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

Date Angular size Mag
20 Dec 210313.0”-0.8
03 Jan 210414.1”-1.1
17 Jan 210414.5”-1.4
31 Jan 210414.0”-1.2
14 Feb 210412.8”-0.8
28 Feb 210411.3”-0.4
13 Mar 210410.0”-0.0
27 Mar 21048.8”0.3
10 Apr 21047.8”0.6
24 Apr 21047.0”0.8
08 May 21046.4”1.0

The sky on 29 Mar 2024

The sky on 29 March 2024
Sunrise
06:56
Sunset
19:30
Twilight ends
21:01
Twilight begins
05:25

19-day old moon
Waning Gibbous

80%

19 days old

Planets
Rise Culm. Set
Mercury 07:25 14:12 20:58
Venus 06:23 12:11 17:59
Moon 23:04 04:01 08:52
Mars 05:41 11:08 16:35
Jupiter 08:39 15:36 22:33
Saturn 06:03 11:39 17:15
All times shown in EDT.

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 Feb 2104  –  Mars ends retrograde motion
13 Jan 2106  –  Mars enters retrograde motion
22 Feb 2106  –  Mars at opposition
22 Feb 2106  –  Mars at perigee

Image credit

© NASA/Hubble Space Telescope

Share

Ashburn

Latitude:
Longitude:
Timezone:

39.04°N
77.49°W
EDT

Color scheme