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.

2140 apparition of Jupiter

06 Jul 2140 – Jupiter enters retrograde motion
04 Sep 2140 – Jupiter at perigee
04 Sep 2140 – Jupiter at opposition
02 Nov 2140 – Jupiter ends retrograde motion

Observing Jupiter

Jupiter enters retrograde motion as its 2140 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 23h08m00s 6°51'S Aquarius -2.6 43.3"

The coordinates above are given in J2000.0.

From Cambridge , it will be visible in the dawn sky, rising at 23:15 (EST) and reaching an altitude of 40° above the southern horizon before fading from view as dawn breaks at around 04:43.

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 Nov 2024

The sky on 26 November 2024
Sunrise
06:46
Sunset
16:13
Twilight ends
17:53
Twilight begins
05:06


Waning Crescent

14%

25 days old

Planets
Rise Culm. Set
Mercury 08:21 12:45 17:10
Venus 10:11 14:36 19:00
Moon 02:14 08:04 13:43
Mars 20:26 03:53 11:20
Jupiter 16:56 00:27 07:58
Saturn 12:46 18:17 23:48
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

06 Jul 2140  –  Jupiter enters retrograde motion
04 Sep 2140  –  Jupiter at opposition
02 Nov 2140  –  Jupiter ends retrograde motion
13 Aug 2141  –  Jupiter enters retrograde motion

Image credit

© NASA/Cassini

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