Coming from far beyond the galaxy, an extremely energetic blast of radio waves has been snared by astronomers lying in wait. Lasting for just a few thousandths of a second, the burst is the first of an enigmatic class of objects to be observed in real-time, astronomers report today in the Monthly Notices of the Royal Astronomical Society.

Called fast radio bursts, these extreme pulses of energy last for just a fraction of a second. They’ve confounded astronomers – who have no idea what they are – since West Virginia University’s Duncan Lorimer reported the first burst in 2007. At the time, it appeared as though the beam of radio waves had traveled