There's no place like home. We wrap up the series with the story of NASA's most experienced female astronaut, Peggy Whitson, as she returns home to earth. We might possibly be the only intelligent life in the universe. Life is rare, complex life rarer, and intelligent life may be an evolutionary bad idea or dead end that is rarer still… and that means that it's possible that we humans may be the only thing in this huge and amazing universe that can appreciate its strangeness with awe and wonder.

• Will Smith
• Michael J. Massimino
• Mae Jemison