Mysterious signal may have been alien call

Extraterrestrial life expert Robert Gray has scoured the (literal) ends of the universe to solve the mystery of the "Wow!" signal. Almost 35 years ago, a radio telescope in Ohio recorded an abnormally urgent signal -- so abnormal, and so strong, that a scientist noted it with a handwritten "Wow!" on a printout of the data. Was this, at last, incontrovertible proof of intelligent alien life? Gray tells The Atlantic that the signal -- "a tug on the cosmic fishing line" -- might represent a sweeping alien call, similar to the beam emitted from a lighthouse: "To operate a beacon that is on all the time, broadcasting in all directions -- the amount of power is enormous," Gray says. "[Aliens] might use some other cheaper strategy -- brief periodic broadcasting, [like] a sweeping lighthouse beam."