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冬季道路上的四重月晕

(原标题: Quadruple Lunar Halo Over Winter Road)

2022-01-02

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有时,落下的冰晶使大气变成一个巨大的透镜,在太阳或月球周围形成弧形和光晕。2012年的一个周六晚上,在西班牙马德里附近,冬天的天空中不仅有一轮明亮的月亮,还有四个罕见的月亮光环。最亮的物体,在特色图像的顶部附近,是月球。来自月球的光通过翻滚的六边形冰晶折射成环绕月球的22度光晕。水平延伸22度弧线是一种更罕见的由柱状冰晶引起的限定光晕。更罕见的是,一些月光透过更远的翻滚的冰晶折射,形成了与月球46度的第三道彩虹状弧线,出现在风景如画的冬季景观上方。此外,整个46度圆晕的一部分也可以看到,所以一个极其罕见的——特别是对月球来说——四重晕被捕获。远处的背景是著名的冬季天空景观,包括天狼星、猎户座带和参宿四——在内外弧线之间可见。光环和弧线通常会持续几分钟到几个小时,所以如果你真的看到了,应该有时间邀请家人、朋友或邻居分享你不寻常的天空景象。

查看原文解释

Sometimes falling ice crystals make the atmosphere into a giant lens causing arcs and halos to appear around the Sun or Moon. One Saturday night in 2012 was just such a time near Madrid, Spain, where a winter sky displayed not only a bright Moon but four rare lunar halos. The brightest object, near the top of the featured image, is the Moon. Light from the Moon refracts through tumbling hexagonal ice crystals into a somewhat rare 22-degree halo seen surrounding the Moon. Elongating the 22-degree arc horizontally is a more rare circumscribed halo caused by column ice crystals. Even more rare, some moonlight refracts through more distant tumbling ice crystals to form a (third) rainbow-like arc 46 degrees from the Moon and appearing here just above a picturesque winter landscape. Furthermore, part of a whole 46-degree circular halo is also visible, so that an extremely rare -- especially for the Moon -- quadruple halo was captured. Far in the background is a famous winter skyscape that includes Sirius, the belt of Orion, and Betelgeuse -- visible between the inner and outer arcs. Halos and arcs typically last for minutes to hours, so if you do see one there should be time to invite family, friends or neighbors to share your unusual lensed vista of the sky.

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