It took astronomers a century to make the first-ever gravitational wave detection, confirming a core prediction of Albert Einstein’s theory of general relativity. But this month, the floodgates have opened.

On Friday, scientists with the Laser Interferometer Gravitational-Wave Observatory (LIGO) announced they’ve likely detected a second gravitational wave event in as many days. Detectors at three locations around the world caught the arrival of a probable ripple in space-time around 11: