60秒后的绿闪日落

2023年10月25日

Gone in 60 Seconds: A Green Flash Sunset
Video Credit & Copyright: Tengyu Cai

Explanation: In 60 seconds, this setting Sun will turn green. Actually, the top of the Sun already appears not only green, but wavey — along with all of its edges. The Sun itself is unchanged — both effects are caused by looking along hot and cold layers in Earth’s atmosphere. The unusual color is known as a green flash and occurs because these atmospheric layers not only shift background images but disperse colors into slightly different directions, like a prism. The featured video was captured earlier this month off the coast of Hawaii, USA. After waiting those 60 seconds, at the video’s end, the upper part of the Sun seems to hover alone in space, while turning not only green, but blue. Then suddenly, the Sun appears to shrink to nothing — only to return tomorrow.

Tomorrow’s picture: 1P/Halley

60秒后的绿闪日落
影片提供与版权: Tengyu Cai

说明: 在60秒之后，这轮夕阳会化为绿闪。实际上，太阳的顶缘不但已是绿色，而且它的可见边缘也都是波浪状的。太阳本身并没改变，上述的这二种效应，都是我们视线方向的地球大气之冷热层所造成的。这种不寻常的现象称为绿闪，其生成是由于这些大气分层不但会让背景影像偏移，也会像三稜鏡一样把色光折到略微不同的方向。这段影片是在本月初摄于美国的夏威夷海岸。经过60秒的等待之后，影像结尾时的太阳顶缘，看似孤伶伶的悬浮在太空中，而且不仅变绿，还更进一步转成蓝。最后很突然的，太阳似乎缩小并直接消失无踪，要看只能等明天了。

明日的图片: 1P/Halley