Uranus ends retrograde motion

Dominic Ford, Editor
From the Outer Planets feed


Objects: Uranus

Uranus 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.

This motion was known to ancient observers, and it troubled them as they could not reconcile it with models in which the planets moved in uniform circular orbits around the Earth, as they believed.

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.

2062 apparition of Uranus

19 Feb 2062 – Uranus enters retrograde motion
05 May 2062 – Uranus at opposition
21 Jul 2062 – Uranus ends retrograde motion

Observing Uranus

Uranus leaves retrograde motion as its 2062 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
Uranus 14h40m50s 15°15'S Libra 5.5 3.8"

The coordinates above are given in J2000.0.

From Fairfield , it will become visible at around 21:37 (EDT), 26° above your south-western horizon, as dusk fades to darkness. It will then sink towards the horizon, setting at 00:42.

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

The sky on 12 Apr 2025

The sky on 12 April 2025
Sunrise
06:16
Sunset
19:29
Twilight ends
21:07
Twilight begins
04:38


Waxing Gibbous

99%

14 days old

Planets
Rise Culm. Set
Mercury 05:26 11:21 17:17
Venus 04:49 11:00 17:10
Moon 18:29 00:16 05:53
Mars 11:56 19:27 02:58
Jupiter 09:05 16:33 00:02
Saturn 05:24 11:15 17:05
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

21 Jul 2062  –  Uranus ends retrograde motion
24 Feb 2063  –  Uranus enters retrograde motion
10 May 2063  –  Uranus at opposition
26 Jul 2063  –  Uranus ends retrograde motion

Image credit

© NASA/Voyager 2

Share