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.

2249 apparition of Mars

01 Feb 2249 – Mars enters retrograde motion
12 Mar 2249 – Mars at opposition
15 Mar 2249 – Mars at perigee
22 Apr 2249 – Mars ends retrograde motion

Observing Mars

Mars leaves retrograde motion as its 2249 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 10h44m50s 10°34'N Leo -0.4 11.5"

The coordinates above are given in J2000.0.

From Fairfield , it will be visible in the evening sky, becoming accessible around 19:48 (EDT), 51° above your south-eastern horizon, as dusk fades to darkness. It will then reach its highest point in the sky at 21:33, 59° above your southern horizon. It will continue to be observable until around 03:21, 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:

25 Feb 2249
25 Mar 2249
22 Apr 2249
20 May 2249
17 Jun 2249

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

Date Angular size Mag
11 Feb 224912.1”-0.6
25 Feb 224913.3”-1.0
11 Mar 224913.9”-1.2
25 Mar 224913.7”-1.1
08 Apr 224912.8”-0.8
22 Apr 224911.5”-0.4
06 May 224910.3”-0.1
20 May 22499.2”0.2
03 Jun 22498.3”0.4
17 Jun 22497.6”0.6
01 Jul 22497.0”0.7

The sky on 1 Oct 2024

The sky on 1 October 2024
Sunrise
06:47
Sunset
18:34
Twilight ends
20:05
Twilight begins
05:15


Waning Crescent

0%

28 days old

Planets
Rise Culm. Set
Mercury 06:51 12:45 18:39
Venus 09:30 14:39 19:47
Moon 05:34 11:57 18:10
Mars 23:43 07:15 14:46
Jupiter 22:03 05:31 12:59
Saturn 17:38 23:12 04:45
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

22 Apr 2249  –  Mars ends retrograde motion
11 Mar 2251  –  Mars enters retrograde motion
18 Apr 2251  –  Mars at opposition
24 Apr 2251  –  Mars at perigee

Image credit

© NASA/Hubble Space Telescope

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