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.

2024–2025 apparition of Uranus

01 Sep 2024 – Uranus enters retrograde motion
16 Nov 2024 – Uranus at opposition
30 Jan 2025 – Uranus ends retrograde motion

Observing Uranus

Uranus leaves retrograde motion as its 2024–2025 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 03h22m10s 18°15'N Aries 5.7 3.6"

The coordinates above are given in J2000.0.

From Cambridge , it will be visible in the evening sky, becoming accessible around 18:04 (EST), 65° above your southern horizon, as dusk fades to darkness. It will then reach its highest point in the sky at 18:24, 65° above your southern horizon. It will continue to be observable until around 23:34, when it sinks below 21° above your western horizon.

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 30 Jan 2025

The sky on 30 January 2025
Sunrise
06:57
Sunset
16:55
Twilight ends
18:32
Twilight begins
05:20


Waxing Crescent

3%

1 day old

Planets
Rise Culm. Set
Mercury 06:49 11:30 16:11
Venus 08:42 14:45 20:49
Moon 08:00 13:02 18:16
Mars 14:43 22:33 06:23
Jupiter 12:12 19:40 03:08
Saturn 08:40 14:18 19:55
All times shown in EST.

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

30 Jan 2025  –  Uranus ends retrograde motion
06 Sep 2025  –  Uranus enters retrograde motion
21 Nov 2025  –  Uranus at opposition
03 Feb 2026  –  Uranus ends retrograde motion

Image credit

© NASA/Voyager 2

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