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.

2076 apparition of Mars

08 Feb 2076 – Mars enters retrograde motion
19 Mar 2076 – Mars at opposition
22 Mar 2076 – Mars at perigee
29 Apr 2076 – Mars ends retrograde motion

Observing Mars

Mars leaves retrograde motion as its 2076 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 11h21m00s 6°22'N Leo -0.5 11.9"

The coordinates above are given in J2000.0.

From Columbus , it will be visible in the evening sky, becoming accessible around 20:44 (EDT), 50° above your south-eastern horizon, as dusk fades to darkness. It will then reach its highest point in the sky at 22:17, 56° above your southern horizon. It will continue to be observable until around 03:51, 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:

04 Mar 2076
01 Apr 2076
29 Apr 2076
27 May 2076
24 Jun 2076

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

Date Angular size Mag
19 Feb 207612.2”-0.7
04 Mar 207613.5”-1.0
18 Mar 207614.2”-1.3
01 Apr 207614.0”-1.1
15 Apr 207613.1”-0.8
29 Apr 207611.9”-0.5
13 May 207610.6”-0.2
27 May 20769.5”0.1
10 Jun 20768.6”0.3
24 Jun 20767.9”0.5
08 Jul 20767.3”0.6

The sky on 3 Jul 2024

The sky on 3 July 2024
Sunrise
06:05
Sunset
21:04
Twilight ends
23:05
Twilight begins
04:03


Waning Crescent

5%

27 days old

Planets
Rise Culm. Set
Mercury 07:39 14:59 22:20
Venus 06:42 14:09 21:35
Moon 03:32 11:27 19:30
Mars 02:45 09:45 16:44
Jupiter 03:52 11:10 18:29
Saturn 00:25 06:07 11:49
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

29 Apr 2076  –  Mars ends retrograde motion
20 Mar 2078  –  Mars enters retrograde motion
26 Apr 2078  –  Mars at opposition
04 May 2078  –  Mars at perigee

Image credit

© NASA/Hubble Space Telescope

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