Jupiter enters retrograde motion

Dominic Ford, Editor
From the Outer Planets feed


Objects: Jupiter

Jupiter will enter retrograde motion, halting its usual eastward movement through the constellations, and turning to move westwards instead. This reversal of direction is a phenomenon that all the solar system's outer planets periodically undergo, a few months before they reach 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 a planet in the outer solar system. Not drawn to scale.

2295 apparition of Jupiter

07 Aug 2295 – Jupiter enters retrograde motion
06 Oct 2295 – Jupiter at perigee
06 Oct 2295 – Jupiter at opposition
03 Dec 2295 – Jupiter ends retrograde motion

Observing Jupiter

Jupiter enters retrograde motion as its 2295 apparition gets underway, although it has already been visible for some weeks in the pre-dawn sky.

Its celestial coordinates as it enters retrograde motion will be:

Object Right Ascension Declination Constellation Magnitude Angular Size
Jupiter 00h55m40s 4°22'N Pisces -2.7 43.7"

The coordinates above are given in J2000.0.

From Fairfield , it will be visible in the morning sky, becoming accessible around 23:12, when it reaches an altitude of 7° above your eastern horizon. It will then reach its highest point in the sky at 04:45, 53° above your southern horizon. It will be lost to dawn twilight around 05:14, 52° above your southern horizon.

Over the following weeks, Jupiter will reach its highest point in the sky four minutes earlier each night, gradually becoming visible in the evening sky, as well as the pre-dawn sky, as it approaches opposition.

The sky on 26 Sep 2024

The sky on 26 September 2024
Sunrise
06:42
Sunset
18:42
Twilight ends
20:14
Twilight begins
05:09


Waning Crescent

24%

23 days old

Planets
Rise Culm. Set
Mercury 06:24 12:32 18:40
Venus 09:18 14:35 19:52
Moon 00:13 08:17 16:12
Mars 23:51 07:23 14:55
Jupiter 22:22 05:50 13:18
Saturn 17:58 23:32 05:07
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

07 Aug 2295  –  Jupiter enters retrograde motion
06 Oct 2295  –  Jupiter at opposition
03 Dec 2295  –  Jupiter ends retrograde motion
13 Sep 2296  –  Jupiter enters retrograde motion

Image credit

© NASA/Cassini

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