How alien can a planet be and still support life?

Science News, April 2016

Just how fantastical a planet can be and still support recognizable life isn’t just a question for science fiction. Astronomers are searching the stars for otherworldly inhabitants, and they need a road map. Which planets are most likely to harbor life? That’s where geoscientists’ imaginations come in. Applying their knowledge of how our world works and what allows life to flourish, they are envisioning what kind of other planetary configurations could sustain thriving biospheres.

A feature story on how unearthly mechanisms could keep planets habitable well outside the traditional "Goldilocks" zone.