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  • Writer's pictureJohn Garcia

Observing the Moon: A Closer Look at First and Last Quarter Phases


The moon, with its ever-changing phases, presents a captivating celestial spectacle that has intrigued humanity for ages. Among the moon's various phases, the First Quarter and Last Quarter hold special significance. These phases offer unique opportunities for observation and exploration. I would like to introduce the characteristics, features, and rewards of observing the moon during the First Quarter and Last Quarter phases, shedding light on the wonders that await those who embark on this lunar journey.

Before beginning with the First Quarter Phase, I would like to begin with the start of the lunar cycle. The lunar cycle begins when the Moon is 'new'. What this means - is the time when the Moon is transiting in front of the Sun, we are unable to see the Moon because the surface facing the Earth is not reflecting light from the Sunlight and of course the Sun is much more brilliant than any other object in the sky. This begins the lunar cycle at day 0.


First Quarter Phase The First Quarter phase occurs when the moon has completed approximately one-quarter of its orbit around the Earth and generally occurs 8 days from being new. During this phase, the moon appears as a half-circle, with the right side illuminated and the left side in darkness. This phase is particularly intriguing for observers due to the striking contrast between light and shadow. The illuminated part reveals exquisite details, including lunar craters, mountain ranges, and vast plains known as Maria.


Observing the First Quarter phase offers a chance to explore the terminator— the line separating the illuminated and dark regions. Along the terminator, shadows cast by mountains and crater rims create a mesmerizing three-dimensional effect. This interplay of light and shadow allows for enhanced visibility of lunar features, making it an excellent time to observe the moon's rugged topography. This is the time I most enjoy viewing the Moon with my telescope.


Last Quarter Phase — The Last Quarter phase occurs when the moon has completed three-quarters of its orbit approximately 16 days after the First Quarter, displaying a similar appearance to the First Quarter phase. However, the illuminated side is now on the left, while the right side is in darkness. This phase provides a fascinating opportunity to observe the moon's western hemisphere, which was not visible during the First Quarter phase.


During the Last Quarter phase, the morning sky becomes the observer's canvas. The contrast between the illuminated crescent and the surrounding darkness creates a serene and mystical ambiance. The Last Quarter phase also unveils a different array of lunar features and brings attention to contrasting geological formations, enhancing the allure of moon observation.


Observation Techniques and TipsTo make the most of observing the moon during the First Quarter and Last Quarter phases, consider the following techniques and tips. Start by selecting a suitable viewing location with minimal light pollution and a clear view of the sky. Utilize binoculars or a telescope to enhance your view and explore the moon's intricate details. Pay attention to the terminator line, where the play of light and shadow is most pronounced. Experiment with different eyepiece filters to highlight specific features or enhance contrast. Additionally, keep a moon map or guidebook handy to identify prominent craters, maria, and other lunar landmarks.


Observing the moon during the First Quarter and Last Quarter phases offers a rewarding experience for both amateur and seasoned astronomers. These phases unveil the moon's captivating features, inviting us to explore its topography, craters, and shadowed regions. By venturing into lunar observation during these phases, we embark on a journey of discovery, immersing ourselves in the ever-changing beauty of Earth's celestial companion. So, grab your binoculars or telescope, find a serene spot under the night sky, and witness the enchantment of the First Quarter and Last Quarter phases as the moon continues its eternal dance through the cosmos.




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January has some very exciting events happening and I am very excited to get setup and observing. I have some new equipment I want to start learning and using now that our backyard project is soon to

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