Astronomers from LIGO and Virgo gravitational wave detectors have detected a collision between two black holes of considerably distinct masses. The Virgo observatory near Pisa, Italy, and the Laser Interferometer Gravitational-Wave Observatory (LIGO), both discovered the event, known as GW190412 on 12 April 2019. The phenomenon provides first obvious evidence from these faint space-time ripples that at least one black hole was spinning before merging, giving astronomers unique insight into a key feature of these dark objects. Astrophysicists believe that detecting spins can shed light on how the black holes developed and came to orbit each other.