Monday's Public Evening lecture at Steward Observatory will not be given by an astronomer.

Paul Bogard, author of "The End of Night: Searching for Natural Darkness in an Age of Artificial Light," will talk about his travels to the darkest and brightest places in the world.

It's a subject of enormous interest to astronomers and to all dark-sky loving afficionados of the cosmos.

Bogard begins his book in Las Vegas, the brightest place he has visited and ends it in Great Basin National Park, the darkest.

Both are in Nevada and therein lies just one of the tales Bogard tells.

His talk begins at 7:30 p.m. at Steward Observatory, 933 N. Cherry Ave., in Room N210, the small auditorium on the west side of the building, next to the historic observatory dome.

A book signing follows the talk and the historic observatory will be open for viewing. The event is free.