New Moon

Thursday 26th Dec 201905:15

The Moon will pass close to the Sun and become lost in the Sun’s glare for a few days.

The Moon‘s orbital motion carries it around the Earth once every four weeks, and as a result its phases cycle from new moon, through first quarter, full moon and last quarter, back to new moon once every 29.5 days.

This motion also means that the Moon travels more than 12° across the sky from one night to the next, causing it to rise and set nearly an hour later each day. Click here for more information about the Moon’s phases.

At new moon, the Earth, Moon and Sun all lie in a roughly straight line, with the Moon in the middle, appearing in front of the Sun’s glare. In this configuration, we see almost exactly the opposite half of the Moon to that which is illuminated by the Sun, making it doubly unobservable because the side we see is unilluminated.

Over coming days, the Moon will rise and set an hour later each day, becoming visible in the late afternoon and dusk sky as a waxing crescent which sets soon after the Sun. By first quarter, in a week’s time, it will be visible until around midnight.

Its day-by-day progress is charted below, with all times are given below in London local time.

Date Sun
sets at
Moon
sets at
Altitude of Moon
at sunset
Direction of Moon
at sunset
26 Dec 2019 15:50 16:09 -1° south-west
27 Dec 2019 15:51 17:05 south-west
28 Dec 2019 15:51 18:06 10° south-west
29 Dec 2019 15:52 19:11 15° south
30 Dec 2019 15:53 20:20 20° south
31 Dec 2019 15:54 21:25 24° south
01 Jan 2020 15:55 22:30 27° south

At the moment of closest approach, it will pass within 0°23'of the Sun, in the constellation Sagittarius. The exact positions of the Sun and Moon will be:

Object Right Ascension Declination Constellation Angular Size
The Moon 18h16m40s -22°59' Sagittarius 31'05"
Sun (centre) 18h16m -23°22' Sagittarius 32'31"

The coordinates above are given in J2000.0.

This entry in the observing calendar was provided by In-The-Sky.org

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