Jupiter ends retrograde motion

Dominic Ford, Editor
From the Outer Planets feed


Objects: Jupiter

2001–2002 apparition of Jupiter

02 Nov 2001 – Jupiter enters retrograde motion
30 Dec 2001 – Jupiter at perigee
31 Dec 2001 – Jupiter at opposition
01 Mar 2002 – Jupiter ends retrograde motion

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.

Observing Jupiter

Jupiter leaves retrograde motion as its 2001–2002 apparition comes to an end, although it will remain visible for some weeks in the dusk sky.

As retrograde motion ends, it will be visible in the evening sky, becoming accessible around 18:04 (PST), 67° above your eastern horizon, as dusk fades to darkness. It will then reach its highest point in the sky at 19:37, 79° above your southern horizon. It will continue to be observable until around 02:02, when it sinks below 7° above your north-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.

As it leaves retrograde motion, its celestial coordinates will be:

Object Right Ascension Declination Constellation Magnitude Angular Size
Jupiter 06h24m20s 23°26'N Gemini -2.4 41.0"

The coordinates above are given in J2000.0.

The sky on 16 Feb 2026

The sky on 16 February 2026
Sunrise
06:33
Sunset
17:36
Twilight ends
19:00
Twilight begins
05:09


Waxing Crescent

0%

0 days old

Planets
Rise Culm. Set
Mercury 07:22 13:10 18:58
Venus 07:09 12:44 18:19
Moon 06:19 11:34 16:57
Mars 06:13 11:31 16:48
Jupiter 14:01 21:10 04:20
Saturn 08:10 14:07 20:05
All times shown in PST.

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

01 Mar 2002  –  Jupiter ends retrograde motion
04 Dec 2002  –  Jupiter enters retrograde motion
02 Feb 2003  –  Jupiter at opposition
03 Apr 2003  –  Jupiter ends retrograde motion

Image credit

© NASA/Cassini

Share