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 3°01' to the south of Mercury. The Moon will be 28 days old.

From South El Monte , the pair will be visible in the dawn sky, rising at 05:14 (PDT) – 1 hour and 34 minutes before the Sun – and reaching an altitude of 12° above the south-eastern horizon before fading from view as dawn breaks at around 06:25.

The Moon will be at mag -8.8 in the constellation Scorpius, and Mercury at mag -0.5 in the neighbouring constellation of Libra.

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 15h49m20s 21°18'S Scorpius -8.8 32'03"5
Mercury 15h49m20s 18°16'S Libra -0.5 5"9

The coordinates above are given in J2000.0. The pair will be at an angular separation of 18° from the Sun, which is in Ophiuchus at this time of year.

The sky on 21 Sep 2025

The sky on 21 September 2025
Sunrise
06:37
Sunset
18:49
Twilight ends
20:13
Twilight begins
05:13


Waxing Crescent

0%

29 days old

Planets
Rise Culm. Set
Mercury 07:11 13:10 19:09
Venus 04:33 11:07 17:42
Moon 06:32 12:41 18:42
Mars 09:04 14:37 20:09
Jupiter 01:13 08:19 15:25
Saturn 18:52 00:47 06:41
All times shown in PDT.

Warning

Never attempt to point a pair of binoculars or a telescope at an object close to the Sun. Doing so may result in immediate and permanent blindness.

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

04 Dec 1966  –  Mercury at greatest elongation west
16 Feb 1967  –  Mercury at greatest elongation east
17 Feb 1967  –  Mercury at highest altitude in evening sky
25 Mar 1967  –  Mercury at highest altitude in morning sky

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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