Since that first detection, scientists have observed three more black hole collisions. (sciencenews.org)
Both the fourth black hole collision and the neutron star crash appeared during a short window of less than a month when all three existing gravitational wave detectors were simultaneously operational. (sciencenews.org)
At the same time, the researchers are upgrading the detectors so that they can spot neutron star and black hole collisions even farther away. (sciencenews.org)