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.

2033–2034 apparition of Uranus

11 Oct 2033 – Uranus enters retrograde motion
25 Dec 2033 – Uranus at opposition
10 Mar 2034 – Uranus ends retrograde motion

Observing Uranus

Uranus leaves retrograde motion as its 2033–2034 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 06h06m40s 23°42'N Gemini 5.6 3.8"

The coordinates above are given in J2000.0.

From Fairfield , it will become visible at around 18:57 (EST), 72° above your southern horizon, as dusk fades to darkness. It will then sink towards the horizon, setting at 02:18.

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 10 Mar 2034

The sky on 10 March 2034
Sunrise
06:10
Sunset
17:52
Twilight ends
19:24
Twilight begins
04:39


Waning Gibbous

73%

20 days old

Planets
Rise Culm. Set
Mercury 05:09 10:19 15:29
Venus 06:54 13:01 19:07
Moon 22:25 03:44 08:58
Mars 08:09 15:07 22:05
Jupiter 06:17 12:02 17:48
Saturn 12:09 19:38 03:06
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

10 Mar 2034  –  Uranus ends retrograde motion
16 Oct 2034  –  Uranus enters retrograde motion
29 Dec 2034  –  Uranus at opposition
14 Mar 2035  –  Uranus ends retrograde motion

Image credit

© NASA/Voyager 2

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