Mercury and Mars will share the same right ascension, with Mercury passing 0°03' to the north of Mars.
From Seattle, the pair will be difficult to observe as they will appear no higher than 11° above the horizon. They will be visible in the dawn sky, rising at 05:15 (PDT) – 1 hour and 34 minutes before the Sun – and reaching an altitude of 11° above the eastern horizon before fading from view as dawn breaks around 06:28.
Mercury will be at mag -0.9, and Mars at mag 1.8, both in the constellation Leo.
The pair will be close enough to fit within the field of view of a telescope, but will also be visible to the naked eye or through a pair of binoculars.
A graph of the angular separation between Mercury and Mars 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 16° from the Sun, which is in Leo at this time of year.
|The sky on 16 September 2017|
26 days old
All times shown in PDT.
Never attempt to point a pair of binoculars or a telescope at an object close to the Sun. Doing so may result in immediate and permanent blindness.
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.
|05 Aug 2017||– Mars at apogee|
|07 Oct 2017||– Mars at aphelion|
|26 Jul 2018||– Mars at opposition|
|31 Jul 2018||– Mars at perigee|