Copyright:
John Rummel
原文:
What’s happening over Bryce Canyon? Two different optical effects that were captured in one image taken earlier this month. Both effects needed to have the Sun situated directly behind the photographer. The nearest apparition was the common rainbow, created by sunlight streaming from the setting sun over the head of the photographer, and scattering from raindrops in front of the canyon. If you look closely, even a second rainbow appears above the first. More rare, and perhaps more striking, are the rays of light that emanate out from the horizon above the canyon. These are known as anticrepuscular rays and result from sunlight streaming though breaks in the clouds, around the sky, and converging at the point 180 degrees around from the Sun. Geometrically, this antisolar point must coincide with the exact center of the rainbows. Located in Utah, USA, Bryce Canyon itself contains a picturesque array of ancient sedimentary rock spires known as hoodoos. APOD Editor to Speak: Saturday, August 8 at Keweenaw Science & Engineering Festival
中文翻譯:
在布萊斯峽谷（Bryce Canyon）上空發生了什麼？這幅圖片在本月早些時候拍攝到兩種不同的光學現象。兩者都需要將太陽直接位於攝影者的背後。最靠近的現象是常見的彩虹，它是由於夕陽的光芒透過攝影者的頭頂，並在峽谷前方的雨滴中散射而形成的。如果仔細觀察，甚至還可以看到第二道彩虹出現在第一道上方。更為罕見且可能更引人注目的是從地平線上方向外輻射的光線，這被稱為反暮光射線（anticrepuscular rays），它是由於陽光透過雲層的縫隙向外流動，並在與太陽相對的180度處聚焦。從幾何學上來看，這個反日點恰好與兩道彩虹的正中心重合。布萊斯峽谷位於美國猶他州，擁有一片古老的沉積岩尖塔，稱為石柱（hoodoos）。
#布萊斯峽谷 #彩虹 #反暮光射線 #自然奇觀 #光學現象 #攝影 #猶他州 #探索自然 #壯觀景色 #科學與藝術
來源:NASA每日圖片
