“ . . . relay this information to Earth. Tsien destroyed three hours ago. I’m only survivor. Using my suit radio — no idea if it has enough range, but it’s the only chance. Please listen carefully. THERE IS LIFE ON EUROPA. I repeat: THERE IS LIFE ON EUROPA. . . “

~ 2010: Odyssey Two by Arthur C. Clarke

Europa, one of the Jupiter’s large moons, holds a special place in the minds of science fiction writers and astrobiologists alike. What sets Europa apart from the other planets and moons in our solar system is that it is covered with a fairly smooth surface layer of frozen water, and its interior is much hotter than its surface, suggesting that there could be a zone of liquid water under that protective layer of ice where life might exist. That easily accessible source of water on its surface could also make Europa a handy refueling stop for space ships exploring the outer solar system — assuming there isn’t the sort of life that destroyed the ill-fated spaceship Tsien in Clarke’s 2010.

In the afterword to 2010, Arthur C. Clarke says his Europans were inspired in part by a 1980 article by Richard C. Hoagland — “The Europa Enigma” — which describes his “quite brilliant concept” that there might be life on Europa. Since then, NASA’s Galileo exploration mission to Jupiter and its moons has provided more detailed information about the moon’s surface