Today’s guest on STEM-Talk is Dr. Chris McKay, a leading astrobiologist and planetary scientist with the Space Science Division of the NASA Ames Research Center in California’s Silicon Valley. Chris’s interview covers a diverse range of topics ranging from the origins of life to the possibility of manned missions to Mars. For the past 30 years, Chris has been advancing our understanding of planetary science. He graduated from Florida Atlantic University in 1975 with a degree in physics and earned a doctorate in astrogeophysics at the University of Colorado in 1982. He was a co-investigator on the Huygens probe to Saturn’s moon Titan in 2005, the Mars Phoenix lander mission in 2008, and the current Mars Science Laboratory mission. His research at NASA has focused on the evolution of the solar system and the origin of life. He also has been heavily involved in NASA’s Mars missions including the current Mars rover — Curiosity.  In addition, Chris has thought deeply about the human exploration of Mars. He has spent considerable time studying polar and desert environments to better understand how humans might survive in Mars-like environments. His research has taken him to the Antarctic Dry Valleys, the Atacama Desert, the Arctic, and the Namib Desert. In 2015, the Desert Research Institute named Chris the Nevada Medalist, which is the highest scientific honor in the state. Links: STEM-Talk Episode 33, interview with NASA’s Natalie Batalha - http://www.ihmc.us/stemtalk/episode-33/ Chris McKay’s NASA profile page - https://spacescience.arc.nasa.gov/staff/chris-mckay/ Show Notes 3:53: Ken and Dawn welcome Chris to the show. 4:05: Dawn asks Chris if it is true that the television series Star Trek inspired him to take up science and start studying planets as a kid. 4:34: Dawn comments on how Apollo happened almost 50 years ago when Chris was a teenager and asks him where he was for Apollo 11 and what it meant to him. 5:24: Ken asks Chris how he learned about Florida Atlantic University, as it was a relatively new university at the time, and asks Chris why he chose it. 6:54: Dawn asks Chris if he was thinking about becoming an astronaut when he decided to major in physics. 7:27: Ken asks Chris what it was like to be a summer intern in the Planetary Biology program at the NASA Ames Research Center around 1980. 8:52: Dawn asks Chris how he chose the University of Colorado, where he earned a PhD in astrogeophysics. 10:42: Dawn asks Chris to discuss his transition from mechanical engineering to astrogeophysics. 12:11: Ken discusses how Chris ended up back at NASA Ames as an astrobiologist and planetary scientist after graduate school. 13:53: Dawn comments how Chris’s research is taking him to extreme places, and asks him to explain what extremophiles are and what their relevance is in the search for life beyond Earth. 17:26: Dawn comments on her experiences searching for extremophiles while working on cave diving projects. 18:12: Dawn asks Chris what his most recent search experience for extremophiles on our planet was. 19:49: Dawn asks Chris what he takes to be the most exciting extremophile discovery out of all of the work he has done. 22:40: Dawn asks Chris to talk about his favorite and least favorite aspects of field research. 24:06: Ken asks Chris to define some terms related to the search for life beyond Earth. Specifically,  whether we have a definition for life itself and if not, what exactly we are searching for when we say we are searching for life. He also asks Chris to talk about alien life and how it differs from life on Earth. 26:21: Ken asks Chris how tough it would be to recognize alien life if it is based on fundamentally different chemistry than life on Earth. 29:16: Ken asks Chris where NASA’s secret alien life storage room is. 31:03: Ken asks Chris what the scientific importance of discovering life in another world is.