The First Quarter Moon - January 6, 2025

Basic Information

• Name: First Quarter Moon
• Phase Order: The third phase of the Moon's eight-phase cycle.
• Appearance: The First Quarter Moon appears half-illuminated, with the right half lit up in the Northern Hemisphere and the left half lit up in the Southern Hemisphere.
• Illumination: Exactly 50% of the Moon's surface is visible from Earth during this phase.

What Happens During the First Quarter Moon?

• The First Quarter Moon occurs when the Moon has completed one-quarter of its orbit around Earth, approximately 7 days after the New Moon.
• This phase marks the transition from the waxing crescent to the waxing gibbous phase.
• The Moon is positioned at a 90-degree angle relative to the Earth and Sun, which is why we see half of its surface illuminated.

Observational Highlights

• Visibility: The First Quarter Moon is visible in the afternoon and evening, setting around midnight.
• Best Time to Observe: This phase is ideal for observing the Moon's surface features, such as craters and mountains, because the shadows cast by the Sun create dramatic contrasts along the terminator (the line dividing the illuminated and dark sides).
• Location in the Sky: The Moon is high in the sky during the evening, making it easy to spot.

Interesting Facts

1. Not Actually "Quarter": Despite its name, the First Quarter Moon is not one-quarter illuminated but rather one-quarter of the way through its orbit around Earth.
2. Cultural Significance: Many cultures use the First Quarter Moon as a marker for timekeeping and agricultural practices.
3. Astronomical Importance: This phase is a great time for amateur astronomers to observe the Moon's surface in detail due to the sharp contrasts created by sunlight.

How to Identify the First Quarter Moon

1. Look for Half Illumination: The Moon will appear as a perfect "half-moon" in the sky, with one side brightly lit and the other in shadow.
2. Time of Day: The First Quarter Moon rises around noon and sets around midnight, making it most visible in the evening.
3. Use a Telescope: A telescope or binoculars will reveal intricate details of the Moon's surface, especially along the terminator.

Personal Note

The snap of the half-moon, at the first quarter of the lunar cycle, took barely a minute to bring up the details on its surface. One can only wonder the mysteries there. The bunch of craters visible in the picture can help identify a handful of them. With the help of AI, the craters that can be identified are:

1. Tycho Crater:

• Located in the southern hemisphere of the Moon.
• A prominent and bright crater with visible rays extending outward, making it one of the most recognizable features.

2. Copernicus Crater:

• Found in the northern hemisphere.
• A large, well-defined crater often referred to as the "Eye of the Moon."

3. Clavius Crater:

• Situated near the Moon's southern pole.
• Notable for its size and the smaller craters within it, forming a unique pattern.

4. Mare Imbrium:

• A large, dark lunar mare (lava plain) visible in the northern hemisphere.
• While not a crater, it is a significant feature of the Moon's surface.

5. Mare Serenitatis:

• Another dark mare located near the center-right of the Moon.
• Its smooth appearance contrasts with the surrounding rugged terrain.

6. Theophilus, Cyrillus, and Catharina Craters:

• A trio of craters near the Moon's terminator (the line dividing light and shadow).
• These craters are located close to each other and are often observed together.