Although its existence has long been suspected, scientists have finally found evidence of water vapor in the atmosphere of an exosolar planet. The feat was accomplished by looking at the spectum of the Sun-like parent star (which is located in the constellation Vulpecula) as the light filtered through the planet's upper atmosphere on its way to Earth. Water vapor in the planet's atmosphere selectively absorbs certain frequencies of infrared radiation, and the tell-tale absorption spectrum was recorded by the Spitzer Space Telescope. The planet itself is one of a class called "Hot Jupiters"—large gaseous planets that orbit especially close to their parent stars—so chances are slim that it harbors any life. One of these days, though, we'll find evidence of life outside the solar system. For PPX players out there, keep an eye out for an upcoming IPO about Earth-like planets... this knowledge might come in handy. —Martha Harbison
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.