Astronomy Cast

If you want to learn about astronomy, Astronomy Cast is a great podcast to listen to. It's a podcast that introduces the general public to diverse topics in astronomy. It not only explains what we know about astronomy, but how we know about things in astronomy (paraphrasing their slogan).

When it first started, I thought I would not learn anything new since most of the topics were those that I had read or heard about before, but I was pleasantly surprised when it turned out that the podcast goes deeper into things without making things difficult.