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 11:20 a.m. E.T. It followed right on the heels of a gravitational wave detection Thursday that sent astronomers racing to observe the event with their telescopes.

In all, it’s the fifth gravitational wave detection this month. And the influx has astronomers excited about kickstarting the era of multi-messenger astronomy, where scientists can combine gravitational wave data with observations from conventional telescopes to gain new insights into extreme cosmic events like colliding black holes and neutron stars.

Scientists suspect Thursday’s event marked the second-ever gravitational wave detection of two colliding neutron stars, the collapsed cores left behind when giant stars go supernova. The merger would have likely spawned a new black hole. Astronomers spent Thursday searching for any signs of the collision on the sky. They’re less certain about the celestial event that led to today’s detection: There’s about a one in seven chance that it was a false alarm caused by earthly vibrations. Its signal is right at the threshold of what LIGO can pick out.

If this latest signal does turn out to be real cosmic collision, though, scientists say that there’s a chance it may be the hallmark of a never-before-seen event: the collision of a neutron star and a black hole. But odds still favor it as a third neutron star merger.