文章介绍了月球的周期性变化，即月相。月球绕地球公转，太阳光照射角度不同，导致我们在地球上看到的月球被照亮的部分发生变化。文章详细解释了新月、娥眉月、上弦月、盈凸月、满月、亏凸月、下弦月、残月这八种主要月相的成因和外观特征。同时，文章还提供了特定日期（7月30日）的月相信息——“渐盈凸月”，并推荐了不同观测工具（肉眼、双筒望远镜、望远镜）可观测到的月球表面特征，如月海、陨石坑以及阿波罗17号着陆点，并提供了查询工具的建议。最后，文章预告了下一次满月日期为8月9日。

🌟 月相的形成源于月球的公转和日、地、月三者相对位置的变化，导致太阳光照射在月球表面不同部分的视角不同，从而在我们看来月球呈现出周期性变化的亮度与形状。整个月球周期约为29.5天，并包含八个主要阶段：新月、渐盈月（娥眉月）、上弦月、渐盈凸月、满月、渐亏凸月、下弦月、渐亏月（残月）。

🔭 在7月30日，月相为“渐盈凸月”，月球表面有32%被照亮。肉眼可见“风暴洋”和“丰饶海”；使用双筒望远镜可观测到“恩底米翁环形山”和“宁静海”，以及“丰饶海”；若使用望远镜，则能清晰看到“阿波罗17号”着陆点，这是人类最后一次登月任务的地点。

📅 文章预告了下一次满月将在8月9日出现，并提及上一次满月发生在7月10日。月相的变化是一个连续且可预测的过程，了解这些周期有助于天文爱好者更准确地进行观测和记录。

💡 月球的八种主要月相依次是：新月（月球被地球和太阳夹在中间，我们看不到被照亮的部分），渐盈月（月球右侧出现一小片光），上弦月（月球右侧一半被照亮，呈半圆形），渐盈凸月（月球大部分被照亮，但未达全圆），满月（月球整个面向地球的一面都被太阳照亮），渐亏凸月（月球右侧开始变暗），下弦月（月球左侧一半被照亮），渐亏月（月球左侧只剩一缕光，直至再次进入新月）。

The moon is becoming more lit up each night as we progress through the lunar cycle.

The lunar cycle is a series of eight unique phases of the moon's visibility. The whole cycle takes about 29.5 days, according to NASA, and these different phases happen as the Sun lights up different parts of the moon whilst it orbits Earth. 

So, what's happening tonight, July 30?

What is today’s moon phase?

As of Wednesday, July 30, the moon phase is Waxing Crescent. There's 32% of the moon's surface visible to us on Earth (according to NASA's Daily Moon Observation).

It's day six of the new lunar cycle, and there's a lot to see on the moon's surface.

With the unaided eye, enjoy a glimpse of the Mare Crisium and the Mare Fecunditatis, an impact basin also known as the "Sea of Fertility." Add binoculars and you'll also get a glimpse of the Endymion Crater and the Posidonius Crater, a lava-filled impact crater that's visible from the fifth to the 19th day of the lunar cycle.

If you have a telescope, you'll also see the Apollo 17, the last moon landing of the Apollo program. Use NASA's interactive moon guide tool to know exactly where to look.

When is the next full moon?

The next full moon will be on August 9. The last full moon was on July 10.

What are moon phases?

According to NASA, moon phases are caused by the 29.5-day cycle of the moon’s orbit, which changes the angles between the Sun, Moon, and Earth. Moon phases are how the moon looks from Earth as it goes around us. We always see the same side of the moon, but how much of it is lit up by the Sun changes depending on where it is in its orbit. This is how we get full moons, half moons, and moons that appear completely invisible. There are eight main moon phases, and they follow a repeating cycle:

New Moon - The moon is between Earth and the sun, so the side we see is dark (in other words, it's invisible to the eye).

Waxing Crescent - A small sliver of light appears on the right side (Northern Hemisphere).

First Quarter - Half of the moon is lit on the right side. It looks like a half-moon.

Waxing Gibbous - More than half is lit up, but it’s not quite full yet.

Full Moon - The whole face of the moon is illuminated and fully visible.

Waning Gibbous - The moon starts losing light on the right side.

Last Quarter (or Third Quarter) - Another half-moon, but now the left side is lit.

Waning Crescent - A thin sliver of light remains on the left side before going dark again.