汇聚在太阳对面的反曙暮辉

2019 June 24

汇聚在太阳对面的反曙暮辉
影像来源及版权:Juraj Patekar

说明：在背对太阳的方向上能看到任何有趣的事物吗？有时候会看到。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-如果排列足够合适的话，一个完整的地球，对面方向的行星，来自行星的辉光，来自行星际尘埃的对日照，彩虹的中心，山上的雾虹，飞机的光环，以及当你的时间，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。在这幅于4月中旬从一架飞机上拍摄的罕见影像中，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。

Anticrepuscular Rays Converge Opposite the Sun
Image Credit & Copyright: Juraj Patekar

Explanation: Is there ever anything interesting to see in the direction opposite the Sun? Sometimes there is. Notable items include your own shadow, a shadow of the Moon during a total solar eclipse, a full moon — in eclipse if the alignment’s good enough, a full earth, planets at opposition, glints from planets, the gegenschein from interplanetary dust, the center of a rainbow, hall-of-mountain fogbows, an airplane glory, and something yet again different if your timing, clouds and Sun position are just right. This different effect starts with clouds near the Sun that are causing common crepuscular rays to stream though. In the featured rare image taken from an airplane in mid-April, these beams were caught converging 180 degrees around, on the opposite side of the sky from the Sun, where they are called anticrepuscular rays. Therefore, it may look like something bright is shining at the antisolar point near the image center, but actually it is reverse-shining because, from your direction, light is streaming in, not out.