Is Anybody out There?

Detection devices are in the works for rooting out extraterrestrial life

In the mid-1960s, the United States Army Corps of Engineers carved a giant cave deep into permafrost in an Alaskan hillside so that scientists could do experiments inside ground that had been frozen for millennia. Entering the 110- meter Cold Region Research and Engineering Laboratory Permafrost Tunnel, as the facility is now known, is like “stepping right back into the Pleistocene,” says astrobiologist Richard Hoover.