Explanation: Why does a cloudy moon sometimes appear colorful? The effect, called a lunar corona, is created by the quantum mechanical diffraction of light around individual, similarly-sized water droplets in an intervening but mostly-transparent cloud. Since light of different colors has different wavelengths, each color diffracts differently. Lunar Coronae are one of the few quantum mechanical color effects that can be easily seen with the unaided eye. Solar coronae are also sometimes evident. The featured composite image was captured a few days before the close Great Conjunction between Saturn and Jupiter last month. In the foreground, the Italian village of Pieve di Cadore is visible in front of the Sfornioi Mountains.
Tomorrow’s picture: magnetic spiral
说明: 为何云内的月亮有时看来七彩缤纷？这种景观称为月华，是月光受到居间几乎透明的云之内，大小均一的小水滴之量子力学绕射所致。因为各种色光的波长不同，故每种色光受到的绕射不同，从而形成月华。因此，月华是少数肉眼轻易可见的量子力学色彩效应之一。在天空，有时也可见到类似的日华景观。这幅组合主题影像，摄于上 个月土星与木星大近合之前数天。影像的前景为意大利的斯福尔诺伊山脉，以及更前方的皮耶·韦迪·卡多雷村。
明日的图片: magnetic spiral