Beneath Europa’s icy crust is a salty ocean, perhaps the best place in the Solar System to look for life. A NASA spacecraft will soon set off to probe the jovian moon

This is Jupiter’s moon Europa—a world as seductive as any in the Solar System—and this is the view that NASA hopes will greet its Europa Clipper spacecraft, which will begin its journey to the Jupiter system next month. Yet, for all the razzle dazzle of Europa’s surface, it is not the main attraction. Something extraordinary is concealed beneath the ice: a liquid saltwater ocean, potentially as clement and welcoming to life as Earth’s.

Equipped with a battery of nine science instruments, Clipper will swoop past Europa in a series of nearly 50 ice-skimming flybys, remotely probing the ocean in hopes of finding a chemistry that could support life.