Astronomers are getting closer to solving one of the universe's biggest mysteries. Fast radio bursts (FRBs) are transient radio pulses that emit more energy in a single millisecond than the sun does all day. As many as 10,000 of them are thought to occur every day but so far astronomers have only spotted dozens and have struggled to pin down their origin.
Throughout its 4.5-billion-year history, Earth has been repeatedly pummeled by space rocks that have caused anything from an innocuous splash in the ocean to species annihilation. When the next big impact will be, nobody knows.