天空中的于韦斯屈莱市

2024年1月25日

Jyväskylä in the Sky
Image Credit & Copyright: Harri Kiiskinen

Explanation: You might not immediately recognize this street map of a neighborhood in Jyväskylä, Finland, planet Earth. But that’s probably because the map was projected into the night sky and captured with an allsky camera on January 16. The temperature recorded on that northern winter night was around minus 20 degrees Celsius. As ice crystals formed in the atmosphere overhead, street lights spilling illumination into the sky above produced visible light pillars, their ethereal appearance due to specular reflections from the fluttering crystals’ flat surfaces. Of course, the projected light pillars trace a map of the brightly lit local streets, though reversed right to left in the upward looking camera’s view. This light pillar street map was seen to hover for hours in the Jyväskylä night.

Tomorrow’s picture: star with planet

天空中的于韦斯屈莱市
影像提供与版权: Harri Kiiskinen

说明: 你可能无法一眼认出这是地球芬兰于韦斯屈莱市（Jyväskylä）的街区地图。不过，这或许是因为此图是在1月16日投射到夜空中，然后由全天相机所拍摄的。拍照时的当地冬夜气温，在摄氏零下20度左右。当冰晶在上方的大气中形成后，洒向头顶天空的街灯之灯光，产生了清楚可见的光柱，而其空灵的外观，则源自飘落的扁平冰晶所造成的镜面反射。路灯所投射的光柱，绘出了当地灯火通明的街道之地图，不过在仰望的相机视角里，景观的左右互换。这幅由光柱所构成的街道图，在于韦斯屈莱市的夜空中飘浮了数小时之久。

明日的图片: star with planet