阿卡迪亚国家公园上空的银河系，美国缅因州 Milky Way over Acadia National Park, Maine (© Harry Collins/Getty Images)

阿卡迪亚国家公园上空的银河系，美国缅因州 Milky Way over Acadia National Park, Maine (© Harry Collins/Getty Images)

繁星闪烁的夜晚 Starry, starry night

Acadia National Park, Maine

This striking photo lets us showcase two noteworthy events in one day, at no extra charge. (You’re welcome.) National Public Lands Day is observed on the fourth Saturday in September, and today’s also part of the Acadia Night Sky Festival, which celebrates the starlit skies over Maine’s gem of a national park.

It’s easy to take our national parks for granted. We certainly appreciate them and enjoy visiting, but today’s commemoration reminds us that they also need our help. National Public Lands Day turns the spotlight on parks and other public lands, inviting everyone to explore but also to volunteer to plant trees, work on trail-maintenance projects, and more. As a bonus: Admission is free today at national parks, monuments, and other participating federal sites.

Acadia is one of the smallest of the nation's 63 national parks, though it attracts an impressive 3 million visitors a year. Aside from its natural beauty, Acadia has some of the most spectacular star-filled night skies in the eastern United States. The natural darkness is protected, with restrictions on outdoor lighting in the park and surrounding areas. The Acadia Night Sky Festival, which started on September 21 and continues through tomorrow, celebrates the natural darkness and the celestial star show. A favorite way to mark the occasion is by kayaking in Castine's harbor, where bioluminescent phytoplankton illuminate the water with a swirling, unearthly glow. With sparkling waters below and out-of-this-world stargazing above, it's been called Acadia's 'Floating Planetarium.'

缅因州阿卡迪亚国家公园

这张引人注目的照片让我们可以在一天内免费展示两件值得关注的事件。（不客气。）9月的第四个星期六是国家公共土地日，今天也是阿卡迪亚夜空节的一部分，庆祝缅因州国家公园瑰宝上星光灿烂的天空。

我们很容易把国家公园视为理所当然。我们当然很感激他们，也很喜欢参观，但今天的纪念活动提醒我们，他们也需要我们的帮助。国家公共土地日将聚光灯转向公园和其他公共土地，邀请每个人探索，也自愿植树，从事小径维护项目等。作为奖励：国家公园、纪念碑和其他参与的联邦网站今天免费入场。

阿卡迪亚是美国63个国家公园中最小的一个，尽管每年吸引了300万游客。除了它的自然美景，阿卡迪亚还有一些美国东部最壮观的充满星星的夜空。自然黑暗受到保护，公园和周边地区的室外照明受到限制。阿卡迪亚夜空节于9月21日开始，持续到明天，庆祝自然的黑暗和天上的星星表演。最受欢迎的庆祝方式是在卡斯廷港划独木舟，在那里，生物发光的浮游植物以漩涡般的、超自然的光芒照亮水面。它的下面和外面都是波光粼粼的海水，俯瞰着天空，被称为阿卡迪亚的“浮动天文馆”。