Here are 190 photos of the aurora stacked to create star trails....

Here are 190 photos of the aurora stacked to create star trails. This shows the rotation of the earth. The star close to the celestial pole, in the center of the circles, is Polaris and is often referred to as the north star. [OC] via /r/spaceporn http://bit.ly/2HhVDgC

via Tumblr http://bit.ly/2Jg7b6t