During a press conference at the American Astronomical Society meeting in San Diego, the second detection of gravitational waves from the merging of two black holes by the LIGO experiment was announced. It is a different event from the first, historic, one announced on February 11, 2016: this time the merger took place about 1.4 billion years ago and was detected on Earth on December 26, 2015. The event is also described in a article published in the journal “Physical Review Letters”.