Astronomical Twilight
Did you know there are actually three different phases of twilight? Civil Twilight is immediately after sunset. Nautical Twilight comes next when it's just dark enough to see the stars (think old-time navigation). Then Astronomical Twilight, which looks quite dark to the naked eye but still not as dark as it can get. In this photo of the Cattle Point Light during Astronomical Twilight, the Milky Way is just starting to be visible. Another 20 minutes and it was totally dark.
