Moon at Last Quarter

Dominic Ford, Editor
From the Moon feed


Objects: The Moon

The Moon will pass last quarter phase, rising in the middle of the night and appearing prominent in the pre-dawn sky.

From Los Angeles, it will be visible from soon after it rises, at 00:32, until soon before it sets at 11:15.

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 last quarter, it rises in the middle of the night and appears high in the sky by dawn. It sets at around lunchtime. More information about the Moon's phases is available here.

The exact moment of last quarter

The exact moment of last 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 last quarter moon can be observed at any time in the pre-dawn sky.

At the moment it reaches last quarter, the Moon's distance from the Earth will be 396,000 km. Its celestial coordinates will be as follows:

Object Right Ascension Declination Constellation Angular Size
The Moon 15h53m20s 14°51'S Libra 30'08"

The coordinates above are given in J2000.0.

The sky on 21 Nov 2024

The sky on 21 November 2024
Sunrise
06:29
Sunset
16:45
Twilight ends
18:13
Twilight begins
05:01


Waning Gibbous

57%

20 days old

Planets
Rise Culm. Set
Mercury 08:19 13:07 17:56
Venus 09:49 14:38 19:27
Moon 21:36 04:51 11:57
Mars 21:13 04:18 11:22
Jupiter 17:50 00:57 08:04
Saturn 13:06 18:44 00:23
All times shown in PST.

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

18 Feb 2036  –  Moon at Last Quarter
26 Feb 2036  –  New Moon
05 Mar 2036  –  Moon at First Quarter
12 Mar 2036  –  Full Moon

Image credit

Simulated image courtesy of Tom Ruen.

Share