Astronomy Picture of the Day——汇聚在太阳对面的反曙暮辉
Anticrepuscular Rays Converge Opposite theSun
Image Credit & Copyright: Juraj Patekar
Explanation: Is there ever anythinginteresting to see in the direction opposite the Sun? Sometimes there is.Notable items include your own shadow, a shadow of the Moon during a totalsolar eclipse, a full moon -- in eclipse if the alignment\\\'s good enough, a fullearth, planets at opposition, glints from planets, the gegenschein frominterplanetary dust, the center of a rainbow, hall-of-mountain fogbows, anairplane glory, and something yet again different if your timing, clouds andSun position are just right. This different effect starts with clouds near theSun that are causing common crepuscular rays to stream through. In the featuredrare image taken from an airplane in mid-April, these beams were caughtconverging 180 degrees around, on the opposite side of the sky from the Sun,where they are called anticrepuscular rays. Therefore, it may look likesomething bright is shining at the antisolar point near the image center, butactually it is reverse-shining because, from your direction, light is streamingin, not out.
汇聚在太阳对面的反曙暮辉
在背对太阳的方向上能看到什么有趣的事儿吗？有时候可以。引人注目的事物包括你自己的影子，日全食期间月球的影子，一轮满月，一个完整的地球，对面方向的行星，来自行星的辉光，彩虹的中心，山上的雾虹，飞机的光环，以及当云层和太阳位置适当时所看到一些与众不同的事物。这种不同的效应始于太阳附近的云层，这些云层会导致常见的曙暮辉光成束通过。在这幅4月中旬从一架飞机上拍摄的罕见图像中，这些光束被捕捉到与太阳呈大约180度的角度汇聚在另一边天空中，被称为反曙暮辉。因此，它看起来更像是在影像中心附近的对日点上闪烁的一些事物，但实际上它是反向发光的，因为从你的方向看去，光是射向你，而不是远离你。
参考文献：
https://apod.nasa.gov/apod/image/1906/AnticrepuscularRays_Patekar_5600.jpg
近期文章：
Astronomy Picture of the Day——雪茄星系的中央磁场