Alien theories understandable after mysterious signals, say scientists

Fast radio bursts have caused more suspicion about extraterrestrial activity

In the 400 years since Galileo Galilei first held a telescope to the heavens, astronomers have laid bare some of the deepest mysteries of the cosmos. They have seen comets crash into planets, found oceans inside moons, and witnessed the shudder of spacetime as black holes collide.

But space remains a realm of the unknown. Writing in the journal Nature on Thursday, scientists in Canada reported the detection of mysterious radio signals from halfway across the universe. It is only the second time that repeating fast radio bursts, or FRBs, have been spotted.