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.

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

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.

Its celestial coordinates as it leaves retrograde motion 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.

From Columbus , it will be visible in the evening sky, becoming accessible around 20:07 (EST), 54° above your south-eastern horizon, as dusk fades to darkness. It will then reach its highest point in the sky at 22:21, 69° above your southern horizon. It will continue to be observable until around 04:36, when it sinks below 9° 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:

01 Feb 2153
01 Mar 2153
29 Mar 2153
26 Apr 2153
24 May 2153

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

Date Angular size Mag
18 Jan 215312.2”-0.7
01 Feb 215313.3”-1.0
15 Feb 215313.8”-1.2
01 Mar 215313.5”-1.0
15 Mar 215312.4”-0.7
29 Mar 215311.1”-0.3
12 Apr 21539.9”-0.0
26 Apr 21538.8”0.3
10 May 21537.9”0.5
24 May 21537.2”0.7
07 Jun 21536.6”0.9

The sky on 26 Nov 2024

The sky on 26 November 2024
Sunrise
07:27
Sunset
17:08
Twilight ends
18:44
Twilight begins
05:51


Waning Crescent

14%

25 days old

Planets
Rise Culm. Set
Mercury 09:00 13:33 18:06
Venus 10:50 15:23 19:56
Moon 03:02 08:53 14:34
Mars 21:21 04:41 12:00
Jupiter 17:51 01:14 08:38
Saturn 13:31 19:04 00:38
All times shown in EST.

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
12 Feb 2155  –  Mars enters retrograde motion
23 Mar 2155  –  Mars at opposition
26 Mar 2155  –  Mars at perigee

Image credit

© NASA/Hubble Space Telescope

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