Sometimes we observe perfectly clear skies, auroral arcs that skirt the edges of the camera's field-of-view, and even the beginning of daylight. Although not all images have aurora in them, it is still important to classify them.
Auroral arc along the edge of the camera's field-of-view
Clear sky with no aurora but a beautiful canopy of stars
Daytime in Yellowknife, NWT, so the image is affected by light saturation
Auroral arc along the edge of the camera's field-of-view
Clear sky with no aurora but a beautiful canopy of stars
Daytime in Yellowknife, NWT, so the image is affected by light saturation