BYR Achieve · 镜像论坛

继承前人的ZZ每日一图081211

2008/12/11镜像同步8 回复

Perseid over Vancouver Credit & Copyright: Yuichi Takasaka (www.blue-moon.ca / TWAN) Explanation: Colorful and bright, the city lights of Vancouver, Canada are reflected in the water in this portrait of the world at night. Recorded on August 12 during the Perseid Meteor Shower, the wide-angle view takes in a large swath along the photographer's eastern horizon. The picture is a composite of many consecutive 2 second exposures that, when added together, cover a total time of an hour and 33 minutes. During that time, stars trailed through the night sky above Vancouver, their steady motion along concentric arcs a reflection of planet Earth's rotation. The dotted trails of aircraft also cut across the scene. Of course, two of the frames captured the brief, brilliant flash of a Perseid fireball as it tracked across the top of the field of view. The large gap in the single meteor trail corresponds to the time gap between the consecutive frames. 温哥华上空的英仙座流星说明: 上图这幅照片中，加拿大温哥华市明亮多彩的都市灯火倒映在水面上。这幅呈现了大片地平线景观的广角影像，同时也记录了2008年8月12日的英仙座流星雨。影像是由许多两秒曝光的照片叠加起来的，总时间达到了1小时33分钟。在这段期间，恒星拖着弧状的流迹移过温哥华市的星空，它们规律性的同心圆弧轨迹是地球自转的结果，而切过影像的点状流迹则来自飞机。其中有两幅照片，在两颗明亮的英仙座火流星掠过影像上方视野时捕捉到了它们的踪迹。每一道流星迹上的断痕，则是流星恰好横跨两幅照片所产生的间隙。

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