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BAA Observing calendar

Conjunction between Saturn and M22

Tuesday, 2018, May 15 - 09:45

Dominic Ford – originally published on

Saturn and M22 will make a close approach, passing within 1°36' of each other.

From London (click to change), the pair will be difficult to observe as they will appear no higher than 14° above the horizon. They will be visible in the morning sky. They will become accessible at around 02:31, when they rise 11° above your south-eastern horizon. They will then reach its highest point in the sky at 04:05, 14° above your southern horizon. They will be lost to dawn twilight at around 04:10, 14° above your southern horizon.

At the moment of closest approach, Saturn will be at mag 0.9, and M22 at mag 5.1, 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 Saturn and M22 at the moment of closest approach will be as follows:

Object Right Ascension Declination Constellation Magnitude Angular Size
Saturn 18h35m50s -22°17' Sagittarius 0.9 17"8
M22 18h36m20s -23°54' Sagittarius 5.1 24"0

The coordinates above are given in J2000.0. The pair will be at an angular separation of 135° from the Sun, which is in Taurus at this time of year.

The details of this observing event were provided courtesy of