The age-old question has been debated for centuries. Might we soon get an answer? The planet that is the current focus of international inquiry is called Gliese 12b, an Earth-sized exoplanet that’s only 40 light years away. The first step in answering this question has to do with determining a planet's habitability. In this respect, Gliese 12b shows some promise. What’s next on the road to solving one of mankind's oldest riddles? Michael McElwain, a NASA scientist at the James Webb Space Telescope center, joins The Excerpt to share insights regarding this revolutionary new development.See Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.