本文介绍了月相变化的科学原理，即太阳光照射月球不同部分，以及月球绕地球公转所产生的周期性现象。文章详细解释了从新月到满月再到残月的八个主要月相，并说明了月相变化与日、月、地三者相对位置的关系。此外，文章还提供了当前（8月11日）的月相信息（盈凸月，94%可见），以及在不同观测条件下（肉眼、双筒望远镜、望远镜）可观测到的月球表面特征，并预告了下一个满月日期。

🌕 月相的形成源于月球围绕地球的公转以及太阳光对月球不同部分的照射。月球的公转周期约为29.5天，这个周期决定了我们从地球上看到的月球被照亮部分的比例不断变化，从而形成不同的月相。

🌙 文章详细列举了月球的八个主要月相：新月（不可见）、峨眉月（一小条亮边）、上弦月（半月，右侧亮）、盈凸月（超过半月但未满）、满月（全亮）、亏凸月（开始变暗）、下弦月（半月，左侧亮）和残月（一小条亮边）。

🔭 文章指出，在8月11日，月相为盈凸月，可见度为94%。通过肉眼可观测到风暴海、静海等月面特征；使用双筒望远镜可看到更细致的陨石坑；而通过望远镜则能观测到更多细节，如阿波罗15号着陆点和席勒环形山。

🗓️ 文章预告了下一个满月日期为9月7日，并回顾了上一个满月日期为8月9日，为对月相变化感兴趣的读者提供了时间参考。

The moon is getting less bright each night following the full moon. Why, you ask? It's to do with 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 with the moon tonight, Aug. 11?

What is today’s moon phase?

As of Monday, Aug. 11, the moon phase is Waning Gibbous, and it is 94% lit up to us on Earth, according to NASA's Daily Moon Observation.

With no visual aids, tonight you can see the Aristarchus Plateau, the Mare Vaporum, and the Mare Serenitatis. Binoculars will reveal even more, with glimpses of the Gassendi Crater and Mare Frigoris. And with a telescope, Apollo 15, the Schiller Crater, and even more will be visible.

When is the next full moon?

The next full moon will be on Sept. 7. The last full moon was on Aug. 9.

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.