The Science of Existence (20-2) Europa

 Europa

Europa is the smallest of the 4 Galilean satellites of Jupiter, the 6th closest around the gas giant. Slightly smaller than the Moon, Europa is the 6th largest moon in the solar system.

Europa is a silicate rock with an iron core. Its tenuous atmosphere is primarily oxygen.

Situated past the planetary snow line, Europa’s surface is H2O ice, 15–25 km thick. Europa’s face is one of the smoothest in the solar system, albeit pockmarked in patterned scratches.

Underneath the ice is a dark, global saltwater ocean, 160 km deep. Turbulence in Europa’s subsurface sea, inspired by Jupiter’s gravitational tugs, causes chaotic cracks on its surface, prompting water plumes that rise 20 times the height of Mt. Everest.

Europa has subduction-driven plate tectonics like Earth, though on Europa, it is an icy shell that submerges into a warmer mantle.

Warmed by internal heat from the core, which creates global convection currents, there may be microbial life in the stormy subsurface sea of Europa.