This happens at around the time when the Moon's orbit carries it around the far side of the Earth as seen from the Sun, at around the same time that it passes full moon.
This distance between the Earth and Moon will be 0.0027 AU (406,000 km).
The exact positions of the Sun and Moon in the sky will be:
|Object||Right Ascension||Declination||Constellation||Angular Size|
The coordinates above are given in J2000.0.
|The sky on 17 December 2021|
13 days old
All times shown in PST.
The circumstances of this event were computed using the DE430 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.
|10 Dec 2021||– Moon at First Quarter|
|18 Dec 2021||– Full Moon|
|26 Dec 2021||– Moon at Last Quarter|
|02 Jan 2022||– New Moon|
Simulated image courtesy of Tom Ruen.