Atmospheric
Optics
Reflected Town Map
Mia Heikkilä caught this extremely unusual sight in the sky over Kauttua/Eura, Finland.
The street lights are reflected in the sky to form an accurate map of the town - see the comparison below.
Light pillars in cold weather are relatively commonplace but this sighting is something different!
Mia's sighting was first published in the Finland astronomy magazine T�hdet ja avaruus.
Bertram Radelow
caught a similar event a few years ago in Davos, Switzerland.
Image ©Mia Heikkilä, shown with permission
In comparison, the more common light pillars (there are some in Mia's image) are from the same crystals but distributed over a range of different heights.
A town map to the approximate scale. the map has been mirrored.
In parts, individual street lights are imaged in the sky.
A thin layer of ice crystals produced the accurate reflection. The closer to the zenith the thicker can be the layer. Directly overhead a relatively thick layer might produce a 'map'. The layer was composed of horizontal plate crystals and their upper and lower hexagonal faces reflected the town lights. The crystals need to be well algned horizontal. There are millions of crystals and collectively they act as a single giant mirror.
