Jupiter ends retrograde motion

Dominic Ford, Editor
From the Outer Planets feed


Objects: Jupiter

Jupiter 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 a planet in the outer solar system. Not drawn to scale.

2199 apparition of Jupiter

25 Jun 2199 – Jupiter enters retrograde motion
24 Aug 2199 – Jupiter at opposition
24 Aug 2199 – Jupiter at perigee
22 Oct 2199 – Jupiter ends retrograde motion

Observing Jupiter

Jupiter leaves retrograde motion as its 2199 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
Jupiter 21h47m40s 14°32'S Capricornus -2.6 43.2"

The coordinates above are given in J2000.0.

From Fairfield , it will be visible in the evening sky, becoming accessible around 18:12 (EDT), 25° above your south-eastern horizon, as dusk fades to darkness. It will then reach its highest point in the sky at 20:34, 34° above your southern horizon. It will continue to be observable until around 00:55, when it sinks below 7° above your south-western horizon.

Over the following weeks, Jupiter will reach its highest point in the sky four minutes earlier each night, gradually disappearing into evening twilight.

The sky on 17 Jul 2024

The sky on 17 July 2024
Sunrise
05:32
Sunset
20:22
Twilight ends
22:22
Twilight begins
03:31


Waxing Gibbous

90%

12 days old

Planets
Rise Culm. Set
Mercury 07:50 14:44 21:39
Venus 06:31 13:47 21:04
Moon 17:22 21:50 02:13
Mars 01:38 08:51 16:03
Jupiter 02:25 09:49 17:12
Saturn 22:51 04:32 10:13
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 Oct 2199  –  Jupiter ends retrograde motion
02 Aug 2200  –  Jupiter enters retrograde motion
01 Oct 2200  –  Jupiter at opposition
28 Nov 2200  –  Jupiter ends retrograde motion

Image credit

© NASA/Cassini

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