Apod 3.7 Yukon Aurora with Star Trails

This image captures, in my opinion, two of the coolest features in the night sky: star trails and auroras. Star trails are created when a camera is attached to a tripod and the camera is left with an open exposure. The camera is centered on the north star, Polaris. As the Earth rotates, the stars slowly traverse the sky surrounding Polaris and when viewed in the camera, you can see the path of the star from the start of the image to the end of it. Auroras occur when reactions between charged particles from the sun and the magnetosphere send particles to the pole, where they interact with the atmosphere, creating colored streaks across the sky. Auroras occur mostly at high latitudes. In areas of high latitude, auroras often occur around the equinoxes. Both the spring and fall equinoxes offer excellent times to see auroras in these high latitude regions. In order to capture both the star trails and the aurora, many short exposure images were combined together to create the star trails so that the aurora could be captured as well.