Conjunction between the Moon and Saturn

2015 Aug 22

Dominic Ford – originally published on

The Moon and Saturn will make a close approach, passing within 2°30' of each other.

From London (click to change), the pair will be difficult to observe as they will appear no higher than 16° above the horizon. They will become visible at around 20:32 (GMT) as the dusk sky fades, 16° above your south-western horizon. They will then sink towards the horizon, setting 3 hours and 4 minutes after the Sun at 23:12.

At the moment of closest approach, the Moon will be at mag -11.8, and Saturn at mag 1.0, both in the constellation 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.

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

Object Right Ascension Declination Constellation Magnitude Angular Size
The Moon 15h48m10s -15°29' Libra -11.8 30'16"0
Saturn 15h46m20s -17°57' Libra 1.0 16"6

The coordinates above are given in J2000.0. The pair will be at an angular separation of 89° from the Sun, which is in Leo at this time of year.

The details of this observing event were provided courtesy of