Conjunction between the Moon and Mars

2018 Mar 10

Dominic Ford – originally published on

The Moon and Mars will make a close approach, passing within 3°47′ 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 02:34 (BST), 3 hours and 52 minutes before the Sun, and attain an altitude of 15° above the southern horizon before fading from view as dawn breaks at around 06:04.

At the moment of closest approach, the Moon will be at mag -11.7, and Mars at mag 0.2, both in the constellation Ophiuchus.

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 17h41m10s -19°26′ Ophiuchus -11.7 29’35″6
Mars 17h39m40s -23°13′ Ophiuchus 0.2 7″1

The coordinates above are given in J2000.0. The pair will be at an angular separation of 83° from the Sun, which is in Aquarius at this time of year.

The details of this observing event were provided courtesy of