Conjunction between the Moon and Neptune

2017 Jan 3

Dominic Ford – originally published on

The Moon and Neptune will make a close approach, passing within 0°22' of each other.

From London (click to change), the pair will become visible at around 16:26 (BST) as the dusk sky fades, 29° above your southern horizon. They will then sink towards the horizon, setting 5 hours and 12 minutes after the Sun at 21:11.

At the moment of closest approach, the Moon will be at mag -11.1, and Neptune at mag 7.9, both in the constellation Aquarius.

At closest approach, the pair will be close enough to fit comfortably within the field of view of a telescope, but will also be visible to the naked eye or a through pair of binoculars.

The precise positions of the Moon and Neptune at the moment of closest approach will be as follows:

Object Right Ascension Declination Constellation Magnitude Angular Size
The Moon 22h45m10s -08°25' Aquarius -11.1 31'07"9
Neptune 22h45m40s -08°46' Aquarius 7.9 2"2

The coordinates above are given in J2000.0. The pair will be at an angular separation of 56° from the Sun, which is in Sagittarius at this time of year.

The details of this observing event were provided courtesy of