Texas-size asteroids make for exciting summer blockbusters, but when it comes to long-term damage, they're not the most menacing threat out there. Lurking at the edge of our galaxy are giant molecular dust clouds -- agglomerations of hydrogen gas, small organic molecules and minerals -- roughly 150 light-years across. If our solar system hit one, it would take 100,000 years to pop out on the other side.
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Science is reinventing play, from extreme sports to gamification to ridiculous roller coasters to the playgrounds of tomorrow, and this issue is chock full of fun. Also, on a less fun note: Did global warming destroy my hometown?