We owe a lot to our wheeled rovers. Opportunity has contributed reams of data concerning the geology of Mars, while Spirit has found possible evidence of past water there. But Spirit is stuck in the sand while Opportunity lumbers slowly toward Endeavor crater at a top speed of 2 inches per second. A team of MIT researchers thinks we can do better, and to prove it they are developing a new kind of planetary explorer that hops, rather that rolls, across a planet's surface.
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.