Fall Aurora

August's darkening nighttime skies start making it possible to see auroras again. The Northern Lights have been out all summer but, since April, high sky brightness has made them invisible.

To see them, look for arc-like structures in the northeast and up as high as the zenith. Their changing intensity, motion and perhaps a hint of green or red color make it possible to distinguish auroral forms from thin clouds.

Remember that auroras are best seen when your eyes are dark-adapted, a process that takes several minutes. Once you look at a car headlight or other bright light source, the adaptation is ruined for a few more minutes.

There is a slight tendency for more auroras to occur in spring and fall than in summer and winter.