What do we really know about the universe? What mysteries are today's top cosmologists investigating? Join a discussion with leading cosmologists to hear fresh perspectives on some of the deepest questions in modern science: What is the mysterious dark matter that fills intergalactic space? Was there another universe before the big bang, and what will happen to ours in the distant future?

With: Jennifer Ouellette, Katherine Freese, Neil Turok, Lawrence Krauss.