In looking back over my posts here at Mister Tristan, I see where a frequent topic has been night running and astronomy (see here on astronomical distances, here for Orion (and specifically the star Sirius), and here for the Perseid meteors, to cite 3 examples).
I can't see how anyone who runs at night can fail to be awed by the heavens and want to learn more, much more. I find myself constantly consulting various astronomy sites to learn about what I was seeing.
One of my favs is Bad Astronomy for an eclectic view of astronomy. Another with more of a layman's approach to understanding what you see in the night sky is Tonight's Sky.
For example, last weekend I was thrilled to see the juxtaposition of Jupiter and the Moon. I had noticed the bright planet very near the moon, but did not know for sure without checking that it was Jupiter. And Venus is particularly bright this week, low in the eastern sky before daybreak.
Of course, no post about astronomy and Ultrarunning would be complete without mentioning the U.S. Naval Observatory's site for Sun and Moon data. I use this site regularly whenever I travel to see when local sunrise and sunset will occur. When you click over there you will notice the term "civil twilight." For ultrarunners, the practical definition is "when can I run without a flashlight?"
You can start about half an hour prior to sunrise and be able to see well enough to not not kill yourself sans flashlight. On the other end, it's the drop-dead time when you better be out of the woods or you're in a heap of trouble.
To use the Naval Observatory site you plug in your location and date to get a customized result. For example, I know I will be in Everett, WA the end of July 2011 for a conference. So on Sunday, 24 July, sunrise is at 5:35 am, with civil twilight beginning at 4:57 am. So I could start a run around 5:00 am without a light. At the end of that Sunday, if I'd choose to run late, the sun sets at 8:55 pm, with civil twilight ending at 9:33 pm. So I could aim for an 8:30 pm finish and have half an hour cushion before full darkness.
Oh, and the moon will rise just after midnight early that Sunday morning, be at its highest at 7:55 am, and set at 3:49 that afternoon. It will be waning, and be about 35% full.