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 4°44' to the south of Mercury. The Moon will be 28 days old.

From Cambridge , the pair will be difficult to observe as they will appear no higher than 10° above the horizon. They will be visible in the dawn sky, rising at 05:21 (EDT) – 1 hour and 42 minutes before the Sun – and reaching an altitude of 10° above the south-eastern horizon before fading from view as dawn breaks at around 06:32.

The Moon will be at mag -8.9 in the constellation Scorpius, and Mercury at mag -0.1 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 15h51m00s 22°05'S Scorpius -8.9 33'17"4
Mercury 15h51m00s 17°21'S Libra -0.1 7"7

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 12 May 2025

The sky on 12 May 2025
Sunrise
05:23
Sunset
19:55
Twilight ends
21:52
Twilight begins
03:27


Waning Gibbous

99%

15 days old

Planets
Rise Culm. Set
Mercury 04:46 11:29 18:11
Venus 03:38 09:50 16:03
Moon 19:22 00:10 04:51
Mars 10:57 18:15 01:33
Jupiter 07:17 14:52 22:27
Saturn 03:26 09:20 15:14
All times shown in EDT.

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

11 Nov 1985  –  Mercury at highest altitude in evening sky
14 Dec 1985  –  Mercury at highest altitude in morning sky
17 Dec 1985  –  Mercury at greatest elongation west
28 Feb 1986  –  Mercury at highest altitude in evening 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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