On this week's podcast, Ars Technica's Jonathan Gitlin recaps The Expanse S02 Episode 11: things go from bad to worse for the Roci crew on Ganymede, Bobbi Draper takes a stand against Mars by defecting to Earth, as things heat up in the Mars/Earth conflict. Then Ars Technica science editor John Timmer talks with authors Amanda Hendrix and Charles Wohlforth about their new book Beyond Earth, which details the challenges of space colonization.