Snap, crackle or pop?

Nature keeps coming up with new and baffling ways to blow things up.

Astronomers have been baffled lately by the mysterious pulses of cosmic energy known as fast radio bursts that seem to pepper the cosmos. In a few unpredictable milliseconds, they typically emit as much energy as the sun does in a day. About 30 of these objects have been discovered deep in space since the first was detected in 2007, all but one burping out a cataclysmic radio pulse exactly once and then disappearing into the night.

Only one burster, known as FRB121102, after the date it was discovered (Nov. 2, 2012), has repeated itself, hundreds of times now.

That allowed Shami Chatterjee of Cornell and his colleagues to track it to a galaxy 3 billion light years away. But that only deepened the mystery of the powers of these objects, and why none are closer to us.

Among the more out-there explanations proffered was that they are lasers propelling alien interstellar spacecraft. That is a scheme that Earthlings themselves are considering to launch a fleet of miniature space probes to Alpha Centauri later this century.