Conjunction between Mars and Saturn

2018 Apr 2

Dominic Ford – originally published on

Mars and Saturn will make a close approach, passing within 1°16' of each other.

From London (click to change), the pair will be difficult to observe as they will appear no higher than 15° above the horizon. They will be visible in the dawn sky. They will rise at 02:55 (BST), 3 hours and 39 minutes before the Sun, and attain an altitude of 15° above the southern horizon before fading from view as dawn breaks at around 06:01.

At the moment of closest approach, Mars will be at mag -0.2, and Saturn at mag 1.1, both in the constellation Sagittarius.

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 Mars and Saturn at the moment of closest approach will be as follows:

Object Right Ascension Declination Constellation Magnitude Angular Size
Mars 18h37m40s -23°32' Sagittarius -0.2 8"5
Saturn 18h37m30s -22°16' Sagittarius 1.1 16"7

The coordinates above are given in J2000.0. The pair will be at an angular separation of 93° from the Sun, which is in Pisces at this time of year.

The details of this observing event were provided courtesy of