Happy first day of fall, northern hemispherans! (Or: Happy autumnal equinox!) Today the hours of daylight equal the hours of night. Historically, our cosmos blog explains, the equinox "was a mile marker for the lived year." NASA says that, for whatever reason, the change of seasons also brings an increase in geomagnetic storms, which we can see in the form of auroras.
A 555-second exposure is centered on Polaris (the north star) as other stars move around it.
Here are a few that were recently added to our Flickr group by Alaska-based photographer Lee Peterson. He writes in an email:
After a summer of having no real nighttime, I walked out ... and saw the first aurora of the late summer season. It was a little after midnight and I had over a solid hour of shooting this magnificent display. Typically displays this intense only last for a few minutes, so it was a real treat to be able to stand outside (with temperatures far above zero) and shoot the aurora.