This oozy, pockmarked image is the surface of Jupiter’s moon Io, from the first complete geologic map of the turbulent orb. Io is the most volcanically active place in the solar system, so it’s of great interest to geologists because its surface is continually refreshing and renewing. It’s the only celestial body where scientists have not seen any impact craters.
Five amazing, clean technologies that will set us free, in this month's energy-focused issue. Also: how to build a better bomb detector, the robotic toys that are raising your children, a human catapult, the world's smallest arcade, and much more.