云层上的极光
(原标题: Aurora over Clouds)
2021-05-30
浏览次数: 34
极光通常发生在云层之上。当从太阳喷射出的快速移动的粒子撞击地球的磁层时，就会产生极光，带电粒子沿着地球的磁场旋转，撞击地球大气层中的原子和分子。例如，氧原子在受到这种碰撞的激励后，会发出通常由极光发出的绿光。极光的最低部分通常出现在大约100公里的高空，而大多数云只存在于大约10公里以下。这张2015年拍摄于冰岛Dyrholaey的特色照片清晰地展示了云层和极光的相对高度。在那里，一位坚定的天体摄影师顶着大风和最初多云的天空，试图捕捉一座风景如画的灯塔上的极光，只是偶然地拍到了沿途包括细长透镜状云的特色照片。在Instagram上关注APOD：英语，波斯语，印度尼西亚语，波斯语或葡萄牙语
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Auroras usually occur high above the clouds. The auroral glow is created when fast-moving particles ejected from the Sun impact the Earth's magnetosphere, from which charged particles spiral along the Earth's magnetic field to strike atoms and molecules high in the Earth's atmosphere. An oxygen atom, for example, will glow in the green light commonly emitted by an aurora after being energized by such a collision. The lowest part of an aurora will typically occur about 100 kilometers up, while most clouds exist only below about 10 kilometers. The relative heights of clouds and auroras are shown clearly in the featured picture in 2015 from Dyrholaey, Iceland. There, a determined astrophotographer withstood high winds and initially overcast skies in an attempt to capture aurora over a picturesque lighthouse, only to take, by chance, the featured picture including elongated lenticular clouds, along the way. Follow APOD on Instagram in: English, Farsi, Indonesian, Persian, or Portuguese
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