What do you get when all the stuff in the universe can’t account for the mass we observe? You get Dark Matter, that mysterious source of gravity that might be the only thing keeping galaxies from flying apart. This week, guest host Rachelle Saunders talk to Carsten Krauss, assistant professor at the physics department of the University of Alberta, about what Dark Matter is, how we discovered it, and how we know it’s there if we can’t actually observe it. And Desiree Schell talks to David Grelli from the Edmonton New Technology Society.