Free Astronomy Magazine November-December 2019

38 EXOPLANETS Science fiction has described uncountable possible extraterrestrial environments and imaginable forms of alien life. But there is also the unimaginable, that is, all that is not conditioned by our knowledge. When we think of a habitable world, we inevitably transfer to it a few things familiar to us, but some scenarios could be entirely inconceiv- able to us and our idea of habitability may prove to be very limited. A flexible concept of the habitability of other worlds by Michele Ferrara revised by Damian G. Allis NASA Solar System Ambassador NOVEMBER-DECEMBER 2019