Last year, the Advanced LIGO-VIRGO gravitational-wave detector network recorded data from 35 merging black holes and neutron stars. A great result—but what did they miss? According to Dr. Rory Smith from the ARC Centre of Excellence in Gravitational Wave Discovery at Monash University in Australia—it’s likely there are another 2 million gravitational wave events from merging black holes, “a pair of merging black holes every 200 seconds and a pair of merging neutron stars every 15 seconds” that scientists are not picking up.
Source:
https://phys.org/news/2020-06-scientists-reveal-lost-billion-years.html