随着新月的临近，未来几晚的月亮将越来越小。这是因为我们正处于29.5天的月球周期中。当前（10月14日星期二）是“残月”阶段，月亮只有42%被照亮，并且可见度将持续降低。即使如此，肉眼仍可观测到第谷环形山、风暴洋和开普勒环形山等月面特征。借助双筒望远镜和望远镜，还可以看到更多细节，包括加森迪环形山、阿尔方斯环形山、弗拉·毛罗高地、席勒环形山以及月面上的一个独特月面漩涡——赖纳尔伽马。下一个满月将在11月5日出现。月相是月球绕地球公转过程中，由于日、地、月三者相对位置不断变化而产生的周期性外观变化。

🌕 当前月相为残月，月亮可见度正在逐渐降低。截至10月14日，仅有42%的月面被照亮，并且这种可见度会持续减小，直至新月。这是一个在满月之后、新月之前的过渡阶段。

🔭 肉眼可见的月面特征包括第谷环形山、风暴洋和开普勒环形山。使用双筒望远镜可以进一步观测到加森迪环形山和阿尔方斯环形山。而通过望远镜，则能更清晰地看到弗拉·毛罗高地、席勒环形山以及月面上独特的赖纳尔伽马月面漩涡。

cyclical 29.5天的月相周期是由于月球围绕地球公转，以及太阳、地球和月球之间相对位置不断变化所致。尽管我们总是看到月球的同一侧，但每晚被阳光照射到的部分会发生变化，从而呈现出不同的月相，包括新月、娥眉月、上弦月、盈凸月、满月、亏凸月、下弦月和残月。

We're inching closer to the New Moon, which means for the next few nights the moon is going to look smaller and smaller to us. This is because of where we are in the lunar cycle, a series of unique phases of the moon that occur over 29.5 days.

What is today’s moon phase?

As of Tuesday, Oct. 14, the moon phase is Waning Crescent. Tonight, only 42% will be lit up, according to NASA's Daily Moon Observation.

Waning Crescent is the last phase before we reach the new moon, and with each day until then, the visibility will decrease. But for now, there's still plenty to see on the moon's surface tonight. With just your naked eye, enjoy a glimpse of the Tycho Crater, Oceanus Procellarum, and the Kepler Crater. With binoculars you'll see even more, including the Gassendi and Alphonsus Craters.

With a telescope, you'll see all this plus the Fra Mauro Highlands, the Schiller Crater, and the Reiner Gamma, a lunar swirl on the moon's surface.

When is the next full moon?

The next full moon will be on Nov. 5.

What are moon phases?

Moon phases are a cycle that occur every 29.5 days, as the moon travels around Earth. The changes happen because the Sun, Earth, and Moon are always moving relative to each other. From here on Earth, the Moon can look full, partly lit, or even completely dark, but we always see the same side. What’s different each night is how much sunlight is hitting it.

The eight main moon phases are:

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. (Northern Hemisphere)

Third Quarter (or Last 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.