Thanks to a surface covered in liquid water, Jupiter's moon Europa serves as the prime suspect for bodies in our solar system harboring extraterrestrial life. For the most part though, speculation has assumed the life on Europa would be microscopic, similar to the chemical and rock-eating microbes found atop undersea volcanic vents on Earth. However, a new study estimates the level of oxygen in Europa's seas may be high enough to support fish-sized life. Hello, alien sushi.
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.