Mercury and Saturn will share the same right ascension, with Mercury passing 0°38' to the south of Saturn.
From Ashburn (click to change) however, the pair will not be observable – they will reach their highest point in the sky during daytime and will be no higher than 7° above the horizon at dawn.
Mercury will be at mag -0.3, and Saturn at mag 0.4, both in the constellation Sagittarius.
The pair will be a little too widely separated to fit comfortably within the field of view of a telescope, but will be visible to the naked eye or through a pair of binoculars.
A graph of the angular separation between Mercury and Saturn around the time of closest approach is available here.
The positions of the two objects at the moment of conjunction will be as follows:
|Object||Right Ascension||Declination||Constellation||Magnitude||Angular Size|
The coordinates above are given in J2000.0. The pair will be at an angular separation of 20° from the Sun, which is in Sagittarius at this time of year.
|The sky on 13 January 2018|
All times shown in EST.
The circumstances of this event were computed using the DE405 planetary ephemeris published by the Jet Propulsion Laboratory (JPL).
This event was automatically generated by searching the ephemeris for planetary alignments which are of interest to amateur astronomers, and the text above was generated based on an estimate of your location.
|15 Jun 2017, 06:05 EDT||– Saturn at opposition|
|27 Jun 2018, 09:15 EDT||– Saturn at opposition|
|09 Jul 2019, 12:55 EDT||– Saturn at opposition|
|20 Jul 2020, 18:15 EDT||– Saturn at opposition|
The Moon in conjunction with Venus and Jupiter, with the Very Large Telescope in the foreground. Image © Y. Beletsky, ESO, 2009.