西南阿连特茹和维森廷海岸自然公园上空的银河，葡萄牙 Milky Way over Southwest Alentejo and Vicentine Coast Natural Park, Portugal (© Daniel Garrido/Getty Images)

西南阿连特茹和维森廷海岸自然公园上空的银河，葡萄牙 Milky Way over Southwest Alentejo and Vicentine Coast Natural Park, Portugal (© Daniel Garrido/Getty Images)

黑夜里的“彩虹” A rainbow's nocturnal cousin

秋季天文周

美国一年里有两次天文日，分别是春季天文日（4月中旬到5月中旬）和秋季天文日（9月中旬至10月中旬）。在这个特别的节日，科学博物馆、天文台、天文俱乐部和天文馆将举办专业人士主持的讲座、展览和工坊活动。对夜空的科学观测从早期文明时代就开始了，而天文学被称为最早的自然科学学科，是研究天体及相关现象的学科。今天照片里的是葡萄牙的西南阿连特茹和维森廷海岸自然公园，这里远离光污染，是个观星的好地方哦。

Fall Astronomy Week

The Milky Way has billions of stars; among them, our own sun finds its place. The galaxy's name is derived from the radiant, pale appearance of the band of stars and gas clouds that graces Earth's sky. Methodical observations of the night sky started with early civilizations but astronomy, the oldest natural science, remains a source of fascination today. It's what brings stargazers to Portugal's Southwest Alentejo and Vicentine Coast Natural Park, a site free from heavy light pollution. Now's a good time to seek out your own celestial spectacle, as it is Astronomy Week and the main event, Saturday's Fall Astronomy Day, this year coincides with the autumnal equinox.