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.

2026–2027 apparition of Jupiter

12 Dec 2026 – Jupiter enters retrograde motion
10 Feb 2027 – Jupiter at perigee
10 Feb 2027 – Jupiter at opposition
12 Apr 2027 – Jupiter ends retrograde motion

Observing Jupiter

Jupiter leaves retrograde motion as its 2026–2027 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 09h17m30s 16°50'N Cancer -2.3 39.5"

The coordinates above are given in J2000.0.

From Columbus , it will be visible in the evening sky, becoming accessible around 20:23 (EST), 63° above your south-eastern horizon, as dusk fades to darkness. It will then reach its highest point in the sky at 21:25, 66° above your southern horizon. It will continue to be observable until around 03:40, when it sinks below 7° above your 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 12 Apr 2027

The sky on 12 April 2027
Sunrise
06:56
Sunset
20:06
Twilight ends
21:42
Twilight begins
05:21


Waxing Crescent

45%

6 days old

Planets
Rise Culm. Set
Mercury 06:30 12:34 18:38
Venus 05:50 11:36 17:23
Moon 10:55 18:49 02:36
Mars 14:43 21:46 04:48
Jupiter 14:23 21:25 04:27
Saturn 06:59 13:18 19:38
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

12 Apr 2027  –  Jupiter ends retrograde motion
12 Jan 2028  –  Jupiter enters retrograde motion
12 Mar 2028  –  Jupiter at opposition
13 May 2028  –  Jupiter ends retrograde motion

Image credit

© NASA/Cassini

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