The Moon and Mars will make a close approach, passing within 1°41' of each other. The Moon will be 27 days old.
From Cambridge, the pair will be visible in the dawn sky, rising at 04:36 (EDT) – 2 hours and 24 minutes before the Sun – and reaching an altitude of 21° above the eastern horizon before fading from view as dawn breaks around 06:41.
The Moon will be at mag -9.6; and Mars will be at mag 1.8. Both objects will lie in the constellation Virgo.
They 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.
A graph of the angular separation between the Moon and Mars around the time of closest approach is available here.
The positions of the pair at the moment of closest approach 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 27° from the Sun, which is in Virgo at this time of year.
|The sky on 17 October 2017|
27 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.
|07 Oct 2017||– Mars at aphelion|
|27 Jul 2018||– Mars at opposition|
|31 Jul 2018||– Mars at perigee|
|16 Sep 2018||– Mars at perihelion|