The Moon and Jupiter will share the same right ascension, with the Moon passing 38' to the north of Jupiter. The Moon will be 27 days old.
At around the same time, the two objects will also make a close approach, technically called an appulse.
From Cambridge , the pair will be visible in the dawn sky, rising at 04:22 (EST) – 2 hours and 44 minutes before the Sun – and reaching an altitude of 18° above the south-eastern horizon before fading from view as dawn breaks at around 06:47.
The Moon will be at mag -10.5, and Jupiter at mag -1.8, both in the constellation Ophiuchus.
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 Jupiter 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 Moon | 17h11m50s | 21°47'S | Ophiuchus | -10.5 | 33'00"2 |
| Jupiter | 17h11m50s | 22°25'S | Ophiuchus | -1.8 | 31"9 |
The coordinates above are given in J2000.0. The pair will be at an angular separation of 40° from the Sun, which is in Sagittarius at this time of year.
The sky on 20 Jan 2031
| The sky on 20 January 2031 | ||||||||||||||||||||||||||||||||||
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8% 27 days old |
All times shown in EST.
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Source
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.
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Image credit
The Moon in conjunction with Venus and Jupiter, with the Very Large Telescope in the foreground. Image © Y. Beletsky, ESO, 2009.