Quarter Moons

The first quarter moon is often considered one of the ideal times for lunar observation. During this phase, half of the Moon illuminated by sunlight... more

by Marcella Giulia Pace

Title

Quarter Moons

Artist

Marcella Giulia Pace

Medium

Photograph - Canvas

Description

The first quarter moon is often considered one of the ideal times for lunar observation. During this phase, half of the Moon illuminated by sunlight is visible from Earth, while the other half is in shadow. This arrangement provides an ideal contrast between the illuminated and shadowed areas, highlighting details on the lunar surface, such as craters, mountains, and plains.



The first quarter moon offers optimal lighting conditions for astronomical observation, as the moonlight is not so intense as to flatten details, but bright enough to allow for clear viewing. This enables a detailed view of the lunar topography and its features.



It is also a favorable time for observing celestial objects beyond the Moon, such as stars and planets, as the moon's brightness is not so intense as to obscure the surrounding sky.





In 2022 I dedicated myself to collecting the quarters of the moon: first quarter and last quarter.



I tried to photograph the Moon, closer to 50% illumination, when the terminator was perpendicular to the horizon and this always happened shortly before or shortly after sunset (for the first quarter) and shortly before or shortly after dawn (last quarter).

https://greenflash.photo/portfolio/a-quarter-of-the-moon-of-2021-2022-and-the-terminator-perpendicular-to-the-horizon/





Within the synodic month or lunar month, the first quarter phase occurs on day 7 and the last quarter phase on day 22

The first and last quarter moon has the characteristic that it rises or sets at midnight or noon and keeps us company in the sky for half the day.

The first quarter moon rises at noon and sets at midnight, the last quarter moon rises at midnight and sets at noon.



The Moons were all photographed with a telephoto lens and at the end of 2022 I chose to position them, with respect to the southern meridian, at the point where they were at the moment I took the shot (i.e., rigorously, when the terminator would have been perpendicular)



I chose as background one of the locations from where I filmed most of the moons, or rather the field near my house, in the Modica countryside.



Some peculiarities of the quarter moon:



1) It is called a quarter of the Moon because, in addition to having covered ¼ of its orbit, the illuminated part we are observing corresponds to half the face of the Moon exposed towards the Earth but to ¼ of the whole Moon.

2) During the last quarter the terminator moves showing the sunset on the lunar surface.

During the first quarter the terminator moves showing the sunrise on the lunar surface



3) The area of the craters near the terminator is very rich for observations and perhaps also for this reason this phase was chosen as the first astronomical photographic shot.



4) The first astronomical photography dates back to March 23, 1840 and takes up the Moon in the last quarter. It was taken by the astronomer Draper https://commons.wikimedia.org/wiki/File:John_W_Draper-The_first_Moon_Photograph_1840.jpg







5) 2022 was also an important year for the Artemis1 mission and the day of departure took place on November 16th when the Moon was in the last quarter.



6) The month of November also contained 3 quarter moon phases: the 1st, 16th and 30th



7) In the first quarter of the Moon, along the terminator, pareidolias can be observed: Lunar x and lunar V (the Moon of February 9 shows a better vision)







8) The half moon has a particular importance in navigation, both on land and at sea, as it allows to determine the position of the north or south cardinal point. For navigation on land, for example, the half moon can be used to determine the direction of true north, as the crescent's arc extends from east to west, with the horizon cutting through the crescent perpendicular to its direction. Looking towards the half moon and finding the midpoint between the two extremes of light, the north-south direction can be identified. Also, for navigation at sea, the half moon can be used to determine the ship's latitude. When the Moon is at its highest point in the night sky, its arc appears horizontal and cuts the local meridian perpendicularly. By measuring the angle between the crescent and the horizon, the ship's latitude can be calculated.



9) The half moon can also be used to estimate local time. Knowing that the crescent is halfway between sunrise and sunset, local time can be estimated by looking at the crescent's position in the sky.

Uploaded

October 23rd, 2023