It’s a fallish day in the Allegheny Mountains of West Virginia, the rural home of Green Bank Observatory and the world’s largest fully steerable telescope. Rippled clouds hang low over the site’s hulking 100-meter radio dish, itself undergirded and overhung by bright white scaffolding. The browning leaves are nearly gone. And the visitor center director, Sherry McCarty, has agreed to give me the astronomy center’s new SETI tour ($40, reservations required).

Learn about your ad choices: dovetail.prx.org/ad-choices