Don’t panic, but mysterious sources have been sending radio signals to Earth for years. Now, scientists have tracked down some of their origins — and they were surprised by what they found.

And no, it’s still not aliens.

Using NASA’s Hubble Space Telescope, astronomers have traced the locations of five deep space signals known as fast radio bursts (FRBs). In a thousandth of a second, these powerful blasts generate as much energy as the sun does in an entire year.