Moon at First Quarter

Dominic Ford, Editor
From the Moon feed


Objects: The Moon

The Moon will pass first quarter phase, appearing prominent in the evening sky and setting in the middle of the night.

From Fairfield , it will be visible from soon after it rises, at 13:57, until soon before it sets at 23:37.

At this time in its monthly cycle of phases, it appears almost exactly half illuminated.

The Moon orbits the Earth once every four weeks, causing its phases to cycle through new moon, first quarter, full moon, last quarter, and back to new moon once every 29.5 days.

As it progresses through this cycle, it is visible at different times of day. At first quarter, it appears high in the sky at sunset before sinking towards the horizon and setting in the middle of the night. More information about the Moon's phases is available here.

Observing the Moon at first quarter

Over coming days, the Moon will set later each day, becoming visible for more of the night. Within a few days, it will not make it very far above the eastern horizon before nightfall. By the time it reaches full phase, it will be visible for much of the night, rising at around dusk and setting at around dawn.

Its daily progress is charted below, with all times are given in Fairfield local time.

Date Sun
sets at
Moon
sets at
Altitude of Moon
at sunset
Direction of Moon
at sunset
09 Oct 202918:2119:12south-west
10 Oct 202918:1920:0114°south-west
11 Oct 202918:1720:5819°south-west
12 Oct 202918:1622:0123°south
13 Oct 202918:1423:0826°south
14 Oct 202918:1300:1528°south
15 Oct 202918:1101:2028°south-east
16 Oct 202918:1002:2426°south-east
17 Oct 202918:0803:2524°south-east
18 Oct 202918:0704:2520°east
19 Oct 202918:0505:2516°east
20 Oct 202918:0406:2411°east

The exact moment of first quarter

The exact moment of first quarter is defined as the time when the Moon's ecliptic longitude is exactly 90° away from the Sun's ecliptic longitude, as observed from the center of the Earth. However, the Moon does not appear in any way special at this instant in time, and a first quarter moon can be observed at any time in the evening sky.

At the moment it reaches first quarter, the Moon's distance from the Earth will be 381,000 km. Its celestial coordinates will be as follows:

Object Right Ascension Declination Constellation Angular Size
The Moon 19h29m20s 19°48'S Sagittarius 31'17"

The coordinates above are given in J2000.0.

The sky on 14 Oct 2029

The sky on 14 October 2029
Sunrise
07:00
Sunset
18:13
Twilight ends
19:44
Twilight begins
05:29


Waxing Gibbous

55%

7 days old

Planets
Rise Culm. Set
Mercury 06:02 11:57 17:53
Venus 11:10 15:39 20:08
Moon 14:19 19:14 00:15
Mars 11:38 16:11 20:43
Jupiter 08:05 13:26 18:47
Saturn 19:44 02:47 09:49
All times shown in EDT.

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.

Related news

14 Oct 2029  –  Moon at First Quarter
22 Oct 2029  –  Full Moon
30 Oct 2029  –  Moon at Last Quarter
05 Nov 2029  –  New Moon

Image credit

Simulated image courtesy of Tom Ruen.

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