Eric Christensen, head of the Catalina Sky Survey, talks about how he and his team hunt asteroids and comets. He explains how astronomers can distinguish between individual asteroids and how new upgrades will let the survey discover more asteroids than ever before.

Dr Jeff Rich stops by the show to talk about variable stars. Some variable stars change brightness dramatically over several hours, and certain types can be used to measure distances. Jeff also explains what it's like to propose for, and get, time on the Hubble Space Telescope.

Brother Guy Consolmagno shares a Coke and talks about the Vatican Observatory, a discovery that got him in trouble with the Voyager team, and why being next to a dairy farm was convenient when he wanted to measure the properties of meteorites.

Dr. Norna Robertson shares a drink from her home country and talks about a specific part of LIGO. She explains that LIGO's eighty-pound mirrors are suspended by four, incredibly thin, silica fibers that were developed just for this project.

Dr. Kanner explains how gravitational waves could teach us about the big bang, and how we might be on the cusp of discovering new phenomena that are so unusual, theorists haven't even predicted their existence.

Dr. Kanner talks about gravitational waves, which were detected for the first time by LIGO last year. He explains how studying neutron stars with gravitational waves can tell us how everyday elements like gold came to be.

Dr. Abby Fraeman returns to the show to talk about Opportunity, the rover that won't quit. Along with its sister rover, Spirit, Opportunity has discovered Mars rocks that could have only formed in the presence of water.

Eric Rice talks about systems engineering and we drink what turns out to be the most disgusting beverage yet. He talks about what it is like to control a spacecraft, and explains why predicting what can go wrong with a spacecraft is a lot simpler than predicting what can go wrong at a wedding.

Dr. Joe Masiero returns to the podcast to talk about asteroid families, which are groups of asteroids that astronomers think are fragments from ancient collisions. He describes how he identifies these families, and how this work can help us understand how the solar system used to be millions of years ago.

Dr Debbie Weiser explains the importance of building an early warning system in the US before a major earthquake hits. Even a few seconds warning is enough to stop elevators, pause surgery, and give peace of mind to everyday folks experiencing aftershocks. To support this program, contact the California Governor's office or your congressional representatives.