Bill Wren remembers exactly where he was when he was first called the Angel of Darkness.

He doesn’t remember the year, but it was at a Texas Star Party, an annual gathering of 500 or so amateur astronomers held at the Prude Ranch in Fort Davis, Texas. Wren, a longtime advocate for the dark skies movement against light pollution as a staffer at UT’s McDonald Observatory, was well known by that point, so a Texas Star Party attendee introduced him to a crowd with a new heavy metal-sounding nickname.

Read more from Chris O’Connell at My San Antonio here.