半穹顶景观点上空的银河，优胜美地国家公园，加利福尼亚州 Milky Way rising above Half Dome in Yosemite National Park, California (© Cory Marshall/Tandem Stills + Motion)

半穹顶景观点上空的银河，优胜美地国家公园，加利福尼亚州 Milky Way rising above Half Dome in Yosemite National Park, California (© Cory Marshall/Tandem Stills + Motion)

你能把灯关掉吗? Could you turn off the lights?

Dark Sky Week

During International Dark Sky Week, we're counting ourselves lucky to have this spectacular nighttime view, considering the astonishing fact that 83% of the global population lives under a light-polluted sky. Unneeded artificial light is classified as a pollutant and has been proven to have harmful side effects. Not only does it waste money and energy, it also disrupts plants and animals, is believed to impact the climate, and blocks our view of the universe.

Encouraging people to get away from artificial light is one of the goals of International Dark Sky Week, and today's photo shows just how magnificent that can be. Here, we're treated to a beautiful view of the Milky Way from Yosemite National Park in California. Yosemite is part of a network of national parks monitoring dark night skies to gather a complete data set of light pollution. They've learned that 'two-thirds of Americans cannot see the Milky Way from their backyard, and if current light pollution trends continue, there will be almost no dark skies left in the contiguous United States by 2025.'

Luckily, dark sky is a recoverable resource. There are ways to reduce our light use and improve the view of the night sky for everyone. Think about it over the course of the next week, preferably while gazing at a night sky undisturbed by light pollution—or at least a beautiful photo of one.

黑暗天空周

在国际黑暗天空周期间，考虑到全球83%的人口生活在轻度污染的天空下这一令人震惊的事实，我们认为自己有幸拥有这一壮观的夜景。不需要的人造光被归类为污染物，并已被证明具有有害的副作用。它不仅浪费金钱和能源，还扰乱动植物，被认为会影响气候，阻碍我们对宇宙的看法。

鼓励人们远离人造光是国际黑暗天空周的目标之一，今天的照片展示了这是多么壮观。在这里，我们可以在加利福尼亚州约塞米蒂国家公园欣赏到银河系的美景。约塞米蒂是国家公园网络的一部分，该网络监测黑夜天空，以收集光污染的完整数据集。他们了解到，“三分之二的美国人无法从自家后院看到银河系，如果目前的光污染趋势继续下去，到2025年，毗邻的美国将几乎没有黑暗的天空。”

幸运的是，黑暗的天空是一种可回收的资源。有一些方法可以减少我们的光线使用，改善每个人的夜空视野。在接下来的一周里好好想想，最好是在凝视没有光污染的夜空时，或者至少是一张美丽的照片。