segunda-feira, 31 de outubro de 2016

Astronomy picture of the day - 2016 October 31 - Ghost Aurora over Canada

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Ghost Aurora over Canada 
Image Credit & Copyright: Yuichi Takasaka
Explanation: What does this aurora look like to you? While braving the cold to watch the skies above northern Canada early one morning in 2013, a most unusual aurora appeared. The aurora definitely appeared to be shaped likesomething , but what? Two ghostly possibilities recorded by the astrophotographer were "witch" and "goddess of dawn", but please feel free to suggest your own Halloween-enhanced impressions. Regardless of fantastical pareidolicinterpretations, the pictured aurora had a typical green color and was surely caused by the scientifically commonplace action of high energy particles from space interacting with oxygen in Earth's upper atmosphere. In the image foreground, at the bottom, is a frozen Alexandra Falls, while evergreen trees cross the middle.