Conjunction of the Moon and Mercury

Dominic Ford, Editor
From the Conjunctions feed


The Moon and Mercury will share the same right ascension, with the Moon passing 1°47' to the south of Mercury. The Moon will be 2 days old.

At around the same time, the two objects will also make a close approach, technically called an appulse.

From South El Monte however, the pair will not be observable – they will reach their highest point in the sky during daytime and will be no higher than 5° above the horizon at dusk.

The Moon will be at mag -9.5, and Mercury at mag 0.1, both in the constellation Virgo.

The pair will be too widely separated to fit within the field of view of a telescope, but will be visible to the naked eye or through a pair of binoculars.

A graph of the angular separation between the Moon and Mercury around the time of closest approach is available here.

The positions of the two objects at the moment of conjunction will be as follows:

Object Right Ascension Declination Constellation Magnitude Angular Size
The Moon 13h16m40s 12°46'S Virgo -9.5 30'31"0
Mercury 13h16m40s 10°58'S Virgo 0.1 6"9

The coordinates above are given in J2000.0. The pair will be at an angular separation of 27° from the Sun, which is in Virgo at this time of year.

The sky on 12 Sep 2025

The sky on 12 September 2025
Sunrise
06:30
Sunset
19:02
Twilight ends
20:27
Twilight begins
05:05


Waning Gibbous

63%

20 days old

Planets
Rise Culm. Set
Mercury 06:28 12:47 19:05
Venus 04:15 11:00 17:44
Moon 21:29 04:44 12:09
Mars 09:11 14:49 20:28
Jupiter 01:42 08:49 15:55
Saturn 19:30 01:25 07:20
All times shown in PDT.

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

18 Sep 1955  –  Mercury at greatest elongation east
29 Oct 1955  –  Mercury at highest altitude in morning sky
29 Oct 1955  –  Mercury at greatest elongation west
11 Jan 1956  –  Mercury at greatest elongation east

Image credit

The Moon in conjunction with Venus and Jupiter, with the Very Large Telescope in the foreground. Image © Y. Beletsky, ESO, 2009.

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