Starting with Nixon and the Apollo missions, we've been blasting presidential signatures into space for more than four decades. This one's the latest: Barack Obama's signature is on Mars rover Curiosity, with Joe Biden's right below it. This shot, of the left side of the rover's deck, was taken by the ever-flexible Curiosity on a recent Martian "sol," or Mars day. Also attached--on the neat, anodized aluminum plaque, which is the material of choice for this sort of thing--are the John Hancocks of various science advisers and NASA officials.
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.