A monthly look at astronomical events in the sky and on Earth

See What’s Up! for August 2019

After the short and light nights of summer, September is the first month in which the sky goes completely dark every night (i.e. astronomical twilight ends, and the sun dips to more than 18° below the horizon). At the start of the month, total darkness runs from 2211 to 0355 BST, but by month end, it runs from 2043 to 0504 BST. So in addition to other delights of the night sky, we can observe faint and diffuse deep sky objects without having to stay up really late.