黄石公园上空的银河

探索宇宙（universe）！每天都会精选一张关于我们迷人宇宙的图片或照片，并附上一段由专业天文学家（astronomer）撰写的简短说明。

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

说明：银河（Milky Way）并非由蒸发的湖泊所形成。这个直径约 10 米的彩色水池被称为 Silex Spring，位于美国怀俄明州的黄石国家公园内。在人工照明下，这些色彩是由生长在温泉中的细菌层所致。蒸汽从温泉中升起，这些温泉是由与黄石热点（Yellowstone Hotspot）相关的地下岩浆加热的。在遥远的背景中，与此无关的银河中心带高悬于头顶，这是一条由数十亿颗恒星（star）照亮的带状区域。这张照片是由 2014 年拍摄的 16 张图像拼接而成的全景图。如果黄石热点再次引发像约 640,000 年前那样的超级火山喷发，北美洲的大部分地区都将受到影响。

Explanation: The Milky Way was not created by an evaporating lake. The colorful pool of water, about 10 meters across, is known as Silex Spring and is located in Yellowstone National Park in Wyoming, USA. Illuminated artificially, the colors are caused by layers of bacteria that grow in the hot spring. Steam rises off the spring, heated by underground magma associated with the Yellowstone Hotspot. Unrelated and far in the distance, the central band of our Milky Way Galaxy arches high overhead, a band lit by billions of stars. The picture features a 16-image panorama taken in 2014. If the Yellowstone Hotspot causes another supervolcanic eruption as it did about 640,000 years ago, a large part of North America would be affected.