Researchers are reanimating 40,000-year-old microbes

Breakthroughs, discoveries, and DIY tips sent every weekday. At the US Army Corps of Engineers' research facility in central Alaska, a unique tunnel descends underground. They were hunting for something much smaller--and smellier. "The first thing you notice when you walk in there is that it smells really bad. It smells like a musty basement that's been left to sit for way too long," geological scientist Tristan Caro recounted in a statement .