The gallery above shows a rare scene: Blue aurora appeared over Santanoni Preserve in Newcomb region of New York, United States, on November 20, 2019. Aurora Borealis were visible in blue color for about half an hour. 

An aurora is also called polar lights, northern lights (aurora borealis), southern lights (aurora australis). It is a natural light display in the earth's sky, predominantly seen in the high-latitude regions, around the Arctic and the Antarctic. According to NASA, aurora can be seen in much of the United States. The farther north you live, the better your chances. In the southern hemisphere, the farther south you live, the better the aurora viewing. 

The color most often associated with the aurora borealis is green. However, blue auroras can be observed sometimes, as well as red, yellow, orange and pink. They are the result of disturbances in the magnetosphere caused by the solar wind. 

(Cover photo via VCG. Edited by An Qi)

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