Episode 2. Sara Walker: If We Find Alien Life, Will We Even Know It?

Kate Adamala is a chemist at the University of Minnesota. In her Protobiology Lab, she is trying to build a synthetic cell from scratch.  Protobiology Lab  Adamala's TEDx talk, "Life But Not Alive"

Donato Giovannelli is an assistant professor at the University of Naples "Federico II." He travels to acid lakes and other extreme environments that are the closest thing today to what Earth was like when life began. Giovannelli's web siteGiovannelli on Twitter

All the life we know is the same: carbon-based, with DNA for genes. (Okay, except for RNA viruses.) But Steven Benner says it doesn't have to be that way. Benner is a Distinguished Fellow at the Foundation for Applied Molecular Evolution. Benner at FFAME

Jeremy England is a physicist at MIT. He has developed an influential theory of life as a way for matter to dissipate energy. England's MIT lab site An article about England in Quanta

We don't know how life got its start. But as more evidence emerges, explains astrobiologist Caleb Scharf, only a few theories are emerging as leading contenders. Scharf is the director of the Columbia Astrobiology Center at Columbia University. calebscharf.com

H. James Cleaves is a professor at the Earth-Life Science Institute in Tokyo and co-author of A Brief History of Creation: Science and the Search for the Origin of Life. Cleaves at ELSI A Brief History of Creation

Sara Imari Walker is a physicist and astrobiologist at Arizona State University. She studies life as a physical phenomenon, in order to develop new ways to search for it elsewhere in the universe. Walker at ASU Walker's TEDx talk about a "universal theory of life."

Carlos Mariscal is a philosopher at the University of Nevada Las Vegas. He collaborates with evolutionary biologists and astrobiologists to explore what it means to be alive. When we ask what is life, Mariscal suggests, we may be asking the wrong question.