Close approach of the Moon and Mars

Saturday 12th Jan 201923:52

The Moon and Mars will make a close approach, passing within 4°58′ of each other. The Moon will be 6 days old.

From London, the pair will be visible in the evening sky, becoming accessible at around 16:41 (BST) as the dusk sky fades, 41° above your southern horizon. They will then reach its highest point in the sky at 17:01, 41° above your southern horizon. They will continue to be observable until around 22:25, when they sink to 8° above your western horizon.

The Moon will be at mag -11.5 in the constellation Cetus, and Mars at mag 0.6 in the neighbouring constellation of Pisces.

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.

At around the same time, the two objects will also share the same right ascension – called a conjunction.

A graph of the angular separation between the Moon and Mars around the time of closest approach is available here.

The positions of the two objects at the moment of closest approach will be as follows:

Object Right Ascension Declination Constellation Magnitude Angular Size
The Moon 00h35m50s -01°35′ Cetus -11.5 29’56″6
Mars 00h28m30s +03°02′ Pisces 0.6 6″8

The coordinates above are given in J2000.0. The pair will be at an angular separation of 75° from the Sun, which is in Sagittarius at this time of year.

This entry in the observing calendar was provided by