What is life? Even as the search for life in the universe evolves, surprisingly, there is no consensus on what life is. We must consider hunting for life not as we know it. 

The existence of extremophiles on Earth has broadened the types of environments in which we might look for life elsewhere in our solar system. And recent missions to dwarf planets has shown that our solar system is replete with the geology that might harbor biology.

In this second episode, Shannon Geary talks with astrobiologist Nathalie Cabrol, the director of the Carl Sagan Center for Research at the SETI Institute about her early interest in astrobiology, meeting Carl Sagan, and the evolving definition of life.