As NASA promised last week, and only slightly delayed by weather, the GRAIL mission to the moon has launched. The twin probes will arrive just as 2012 dawns, and map the gravitational field and the interior characteristics of our nearest neighbor.
Read our full coverage of the mission here.
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.