Mars ends retrograde motion

Dominic Ford, Editor
From the Outer Planets feed


Objects: Mars

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.

2044 apparition of Mars

31 Jan 2044 – Mars enters retrograde motion
11 Mar 2044 – Mars at opposition
14 Mar 2044 – Mars at perigee
21 Apr 2044 – Mars ends retrograde motion

Observing Mars

Mars leaves retrograde motion as its 2044 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 10h53m20s 9°40'N Leo -0.5 11.6"

The coordinates above are given in J2000.0.

From Cambridge , it will be visible in the evening sky, becoming accessible around 19:55 (EDT), 50° above your south-eastern horizon, as dusk fades to darkness. It will then reach its highest point in the sky at 21:34, 57° above your southern horizon. It will continue to be observable until around 03:21, when it sinks below 8° above your 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 panels below show the month-by-month change in Mars' apparent size in coming weeks, as it recedes from the Earth:

25 Feb 2044
24 Mar 2044
21 Apr 2044
19 May 2044
16 Jun 2044

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

Date Angular size Mag
11 Feb 204412.2”-0.6
25 Feb 204413.4”-1.0
10 Mar 204414.0”-1.3
24 Mar 204413.8”-1.1
07 Apr 204412.8”-0.8
21 Apr 204411.6”-0.5
05 May 204410.4”-0.1
19 May 20449.3”0.1
02 Jun 20448.4”0.4
16 Jun 20447.7”0.6
30 Jun 20447.1”0.7

The sky on 7 May 2024

The sky on 7 May 2024
Sunrise
05:29
Sunset
19:50
Twilight ends
21:44
Twilight begins
03:35


Waning Crescent

0%

29 days old

Planets
Rise Culm. Set
Mercury 04:40 11:03 17:26
Venus 05:16 12:11 19:05
Moon 04:56 12:11 19:41
Mars 03:55 10:01 16:07
Jupiter 05:59 13:13 20:27
Saturn 03:17 08:55 14:33
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

21 Apr 2044  –  Mars ends retrograde motion
10 Mar 2046  –  Mars enters retrograde motion
17 Apr 2046  –  Mars at opposition
24 Apr 2046  –  Mars at perigee

Image credit

© NASA/Hubble Space Telescope

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