Dr. Dan Petrizzo explains what isotopes are, and what isotopes in water can tell scientists about ancient climates. He also explains how he made Mars rocks in the lab.
Professor Amy Lovell talks about listening in on radio waves coming from comets, as well as the particular challenges of using the world's biggest radio telescopes.
Professor Bethanny Ehlmann discusses how to pick a landing site for NASA's next Mars rover, Mars 2020. Over a particularly good beer, we also cover looking for life on Mars, and she answers the thorny question: why look for life on Mars, which has little
Dr Bonnie Buratti talks about Pluto's big mystery: What is the source of energy that is causing all the active geology seen by New Horizons?