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.

2007 apparition of Jupiter

05 Apr 2007 – Jupiter enters retrograde motion
05 Jun 2007 – Jupiter at opposition
07 Jun 2007 – Jupiter at perigee
06 Aug 2007 – Jupiter ends retrograde motion

Observing Jupiter

Jupiter leaves retrograde motion as its 2007 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 16h33m00s 21°24'S Ophiuchus -2.4 40.3"

The coordinates above are given in J2000.0.

From Columbus , it will be visible in the evening sky, becoming accessible around 20:59 (EDT), 28° above your southern horizon, as dusk fades to darkness. It will then reach its highest point in the sky at 21:04, 28° above your southern horizon. It will continue to be observable until around 00:57, 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 10 Apr 2025

The sky on 10 April 2025
Sunrise
06:59
Sunset
20:04
Twilight ends
21:40
Twilight begins
05:24


Waxing Gibbous

98%

12 days old

Planets
Rise Culm. Set
Mercury 06:09 12:05 18:01
Venus 05:35 11:46 17:58
Moon 17:08 --:-- 05:55
Mars 12:43 20:10 03:38
Jupiter 09:54 17:19 00:43
Saturn 06:10 12:01 17:51
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

06 Aug 2007  –  Jupiter ends retrograde motion
09 May 2008  –  Jupiter enters retrograde motion
09 Jul 2008  –  Jupiter at opposition
08 Sep 2008  –  Jupiter ends retrograde motion

Image credit

© NASA/Cassini

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