Gladysheva, O.G. Atmospheric Anomalies in the Summer of 1908: Skyglow. // Geomagnetism and Aeronomy 52(4). 526–532. 2012. doi: 10.1134/S001679321203005X
After the Tunguska catastrophe, the region of “white nights” extended southwards as far down as ~42°N at some locations. Impressive sunsets, colored in all shades of the solar spectrum were observed in the territory of Europe and some parts of Asia from 47 to 60°N. These phenomena can be explained by the reflection of sunlight from the internal Earth-facing surface of the noctilucent cloud field ~10 mln. km2 in area. The reflective surface of the noctilucent cloud field after the Tunguska catastrophe was estimated to be by a factor of 104 larger than the reflective surface of usual noctilucent clouds.