Guest: Jim Kaler.

Today on Focus, we'll discuss how modern astronomers have come to understand the stars with Jim Kaler, author of The Little Book of Stars. The book tells the story of the stars, from their births to their violent deaths. It also looks at how humans have used the stars to keep time and to navigate, and explains what stars have taught us about the forces at work in the universe. We'll tackle all this and more on the show.