Conjunction between the Moon and Mars

2015 Jan 23

Dominic Ford – originally published on

The Moon and Mars will make a close approach, passing within 3°44' of each other.

From London (click to change), the pair will become visible at around 16:53 (GMT) as the dusk sky fades, 22° above your south-western horizon. They will then sink towards the horizon, setting 3 hours and 19 minutes after the Sun at 19:46.

At the moment of closest approach, the Moon will be at mag -10.3, and Mars at mag 0.9, both in the constellation Aquarius.

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.

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

Object Right Ascension Declination Constellation Magnitude Angular Size
The Moon 22h36m00s -05°47' Aquarius -10.3 33'04"9
Mars 22h40m30s -09°21' Aquarius 0.9 4"5

The coordinates above are given in J2000.0. The pair will be at an angular separation of 35° from the Sun, which is in Capricornus at this time of year.

The details of this observing event were provided courtesy of