Dominic Ford, Editor
From the Conjunctions feed
The Moon and Mercury will share the same right ascension, with the Moon passing 0°51' to the north of Mercury. The Moon will be 2 days old.
From Cambridge, the pair will be difficult to observe as they will appear no higher than 8° above the horizon. They will become visible around 20:29 (EDT) as the dusk sky fades, 8° above your western horizon. They will then sink towards the horizon, setting 1 hour and 11 minutes after the Sun at 21:19.
The Moon will be at mag -9.5, and Mercury at mag 0.2, both in the constellation Leo.
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 the Moon and Mercury 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 26° from the Sun, which is in Cancer at this time of year.
|The sky on 25 July 2017|
2 days old
All times shown in EDT.
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.
|16 Jul 2017||– Mercury reaches highest point in evening sky|
|29 Jul 2017||– Mercury at greatest elongation east|
|12 Sep 2017||– Mercury at greatest elongation west|
|14 Sep 2017||– Mercury reaches highest point in morning sky|
The Moon in conjunction with Venus and Jupiter, with the Very Large Telescope in the foreground. Image © Y. Beletsky, ESO, 2009.