2025年2月4日
Anticrepuscular Rays: A Rainbow Fan over Spain
Image Credit & Copyright: Julene Eiguren
Explanation: Yes, but can your rainbow do this? Late in the day, the Sun set as usual toward the west. However, on this day, the more interesting display was 180 degrees around — toward the east. There, not only was a rainbow visible, but an impressive display of anticrepuscular rays from the rainbow’s center. In the featured image from Lekeitio in northern Spain, the Sun is behind the camera. The rainbow resulted from sunlight reflecting back from falling rain. Anticrepuscular rays result from sunlight, blocked by some clouds, going all the way around the sky, overhead, and appearing to converge on the opposite horizon — an optical illusion. Rainbows by themselves can be exciting to see, and anticrepuscular rays a rare treat, but capturing them both together is even more unusual — and can look both serene and surreal.
Jigsaw Challenge: Astronomy Puzzle of the Day
Tomorrow’s picture: comet set
反云隙光: 西班牙上空的彩虹扇
影像提供与版权: Julene Eiguren
说明: 对了，你看到的彩虹有这么精采吗？在那天的傍晚时分，太阳一如往常的西落，然而，此时最吸睛的，反而是与落日180度反向的东方景观。于东方的天空中，不仅看见一道美丽的彩虹，还能见到看似从彩虹中心射出的反云隙光。在这张摄于西班牙北部勒基蒂奥镇的照片里，太阳位于摄影者身后。彩虹是阳光被雨滴反射的产物，而反云隙光是因为阳光被云层部分遮挡所产生的影子，然后在穿过天空后，看似会聚于180度反向地平线上的光学幻觉。彩虹本身就已经够精采，反云隙光则是罕见的光学现象，而能将二者同时捕捉入镜，不仅非常难得，更成就了既静谧又梦幻的奇景。
拼图挑战: 每日天文学拼图
明日的图片: comet set
