扮成土星的月亮
2022年8月2日
A Moon Dressed Like Saturn
Image Credit & Copyright: Francisco Sojuel
Explanation: Why does Saturn appear so big? It doesn’t — what is pictured are foreground clouds on Earth crossing in front of the Moon. The Moon shows a slight crescent phase with most of its surface visible by reflected Earthlight known as ashen glow. The Sun directly illuminates the brightly lit lunar crescent from the bottom, which means that the Sun must be below the horizon and so the image was taken before sunrise. This double take-inducing picture was captured on 2019 December 24, two days before the Moon slid in front of the Sun to create a solar eclipse. In the foreground, lights from small Guatemalan towns are visible behind the huge volcano Pacaya.
News: APOD Receives First Outreach Prize from the International Astronomical Union
Tomorrow’s picture: in a cat’s eye
扮成土星的月亮
影像提供与版权: Francisco Sojuel
说明: 为什么土星看起来那么大？没这回事，我们所见到的，其实是月亮前方有地球的云飘过。此轮明月是仅存一抹银白的新月，其余的大部分月面，则因为受到名为灰光的地球反照光之照耀而隐约可见。受太阳光直接照耀的月盘是在下缘，这也意味着太阳必然在地平线下方，因此这幅影像是摄于日出之前。这张双重引人入胜的照片，摄于2019年12月24日，亦即在月亮行进到太阳前方，造成日食的前二天。在影像前景里，庞然的帕卡亚火山后方，有来自瓜地马拉数个小城镇的灯火。
明日的图片: in a cat’s eye