美国佛罗里达州上空的夜光云

美国佛罗里达州上空的夜光云

Noctilucent Clouds over Florida
Credit & Copyright: Pascal Fouquet

Explanation: These clouds are doubly unusual. First, they are rare noctilucent clouds, meaning that they are visible at night — but only just before sunrise or just after sunset. Second, the source of these noctilucent clouds is actually known. In this rare case, the source of the sunlight-reflecting ice-crystals in the upper atmosphere can be traced back to the launch of a nearby SpaceX rocket about 30 minutes earlier. Known more formally as polar mesospheric clouds, the vertex of these icy wisps happens to converge just in front of a rising crescent Moon. The featured image — and accompanying video — were captured over Orlando, Florida, USA about a week ago. The bright spot to the right of the Moon is the planet Jupiter, while the dotted lights above the horizon on the right are from an airplane.

Tomorrow’s picture: open space

美国佛罗里达州上空的夜光云
影像提供与版权: Pascal Fouquet

说明: 这团云有二个不寻常之处。首先，它是罕见的夜光云，意即它是夜晚才可见的云种，而且可见时段紧在日出前或日落后。其次，这团夜光云的起源已知。在此一稀有的案例里，这片在高层大气中反射阳光的冰晶之来源，可以回溯到大约30分钟前，于附近发射的一枚太空探险公司的火箭。这团正式名称为极地中气层云的冰晶云，其絮丝状涡旋的核心恰好位于东升的新月前方。这张主题影像和附随的影片，是大约在一星期前摄于美国 佛罗里达州的奥兰多市。月亮右方的光点是木星，而右侧地平线上方的虚线状光迹则是来自一架飞机。

明日的图片: open space