The Cassini spacecraft buzzed past Saturn's moon Iapetus yesterday, coming within 1,000 miles of its surface. The walnut-shaped moon has a band of relatively large mountains running around its equator, and appears two-toned, with one hemisphere bright and the other dark as night. Cassini flew by it in 2004, but it's going to be 100 times closer this time, and scientists hope this final look will help them figure out some of Iapetus's strange features. The results of some of the data gleaned will be presented at a planetary science conference in October.—Gregory Mone
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.