February auroras and blue flashes

A CME impact followed by a gusty solar wind stream have combined to produce bright lights around the Arctic Circle on Feb. 26-29.  Arctic sky watchers should be on alert for more auroras tonight.

The green flash, the fleeting emerald light that sometimes appears just above the setting sun (Once thought to be a fable, the green flash was popularized by Jules Verne in his 1882 novel “Le Rayon Vert”).  Peter Rosén photographed rare blue flash from Stockholm, Sweden, on Feb. 29th as it can be seen below.

A mirage magnifies tiny differences in the atmospheric refraction of red, green and blue light. Blue flashes are generally harder to see than green flashes, because blue flashes blend into the surrounding blue sky. When the air is exceptionally clear, however, the blue flash emerges. (SpaceWeather)

Featured image: Aurora over Vaasa, Finland (Credit: Kaj Hoglund)