The Moon and Mercury will share the same right ascension, with the Moon passing 6°09' to the south of Mercury. The Moon will be 28 days old.
From Columbus , the pair will be difficult to observe as they will appear no higher than 9° above the horizon. They will be visible in the dawn sky, rising at 06:19 (EST) – 1 hour and 27 minutes before the Sun – and reaching an altitude of 9° above the south-eastern horizon before fading from view as dawn breaks at around 07:21.
The Moon will be at mag -8.5 in the constellation Scorpius, and Mercury at mag -0.5 in the neighbouring constellation of Ophiuchus.
The pair will be too widely separated to fit within the field of view of a telescope or pair of binoculars, but will be visible to the naked eye.
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 | 16h27m10s | 26°46'S | Scorpius | -8.5 | 29'26"2 |
| Mercury | 16h27m10s | 20°37'S | Ophiuchus | -0.5 | 5"5 |
The coordinates above are given in J2000.0. The pair will be at an angular separation of 17° from the Sun, which is in Sagittarius at this time of year.
The sky on 18 Dec 2025
| The sky on 18 December 2025 | ||||||||||||||||||||||||||||||||||
|
1% 28 days old |
All times shown in EST.
|
|||||||||||||||||||||||||||||||||
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
| 07 Dec 2025 | – Mercury at greatest elongation west |
| 19 Feb 2026 | – Mercury at greatest elongation east |
| 20 Feb 2026 | – Mercury at highest altitude in evening sky |
| 27 Mar 2026 | – 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.