Conjunction between the Moon and Neptune

2017 Jul 13

Dominic Ford – originally published on

The Moon and Neptune will make a close approach, passing within 0°49' of each other.

From London (click to change), the pair will be visible in the dawn sky. They will rise at 23:06 (BST), 5 hours and 55 minutes before the Sun, and attain an altitude of 31° above the southern horizon before fading from view as dawn breaks at around 04:32.

At the moment of closest approach, the Moon will be at mag -12.4, and Neptune at mag 7.8, both in the constellation Aquarius.

The pair will be a little too widely separated to fit comfortably within the field of view of a telescope, but will 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 23h02m40s -07°59' Aquarius -12.4 30'44"3
Neptune 23h01m40s -07°12' Aquarius 7.8 2"3

The coordinates above are given in J2000.0. The pair will be at an angular separation of 127° from the Sun, which is in Gemini at this time of year.

The details of this observing event were provided courtesy of