一组月相照片 Composite photo showing the phases of the moon (© Delpixart/Getty Images)

一组月相照片 Composite photo showing the phases of the moon (© Delpixart/Getty Images)

人类迈出的一大步 One giant leap for mankind

National Moon Day

Bigger and brighter than anything else you can see from Earth in the night sky, the moon has inspired our calendar, our songs, our art, our stories, and our dreams. Today, on National Moon Day, we remember one dream that came true on this date in 1969: the day humans first set foot on the lunar surface. So far, it's the only place beyond our planet that humans have visited.

Fifty-three years ago, millions of people around the world watched NASA astronaut Neil Armstrong step out of the Apollo Lunar Module Eagle and onto the surface of the moon. Fellow astronaut Buzz Aldrin followed him 19 minutes later, and the pair spent more than two hours exploring the landing site and collecting samples of lunar material. They and a third astronaut, Michael Collins—who flew the command module that took them back to Earth and did not have a moon walk of his own—spent eight days in space before splashing down in the Pacific Ocean. The moon landing gave the US a victory in the Space Race with the Soviets.

The moon is Earth's only natural satellite, orbiting our planet about every 28 days, what we refer to as a lunar cycle. The moon has virtually no atmosphere, no evidence of life, no water, no sound, and very low gravity. It is literally a dusty ball of rock. Yet, the moon stabilizes Earth's wobble on its axis and therefore moderates our climate. Most scientists believe it was formed out of debris ejected from Earth after a massive collision with another planet-like body. If that's true, the moon is part of Earth, inextricably linked forever.

国家月球日

月亮比你在夜空中从地球上看到的任何东西都更大、更明亮，它激发了我们的日历、我们的歌曲、我们的艺术、我们的故事和我们的梦想。今天，在国家月球日，我们记得1969年这个日子实现的一个梦想：人类首次踏上月球表面的那一天。到目前为止，它是地球之外唯一一个人类去过的地方。

五十三年前，全世界数百万人观看了美国宇航局宇航员尼尔·阿姆斯特朗走出阿波罗登月舱“鹰”登上月球表面。19分钟后，另一名宇航员巴兹·奥尔德林跟随他，两人花了两个多小时探索着陆点并收集月球物质样本。他们和第三名宇航员迈克尔·柯林斯（Michael Collins）在太空中度过了八天，然后坠入太平洋。迈克尔·柯林斯驾驶着指挥舱将他们带回了地球，他自己也没有进行过月球行走。登月使美国在与苏联的太空竞赛中取得了胜利。

月球是地球上唯一的天然卫星，大约每28天绕地球一周，我们称之为月球周期。月球几乎没有大气层，没有生命迹象，没有水，没有声音，重力很低。它实际上是一个尘土飞扬的岩石球。然而，月球稳定了地球在其轴线上的摆动，因此缓和了我们的气候。大多数科学家认为，它是由与另一个类似行星的物体发生大规模碰撞后从地球上喷出的碎片形成的。如果这是真的，那么月球是地球的一部分，永远是密不可分的。