An article published in the journal “Nature” reports the detection of neutrinos produced by the Sun by the Borexino experiment. The scientists of the Borexino Collaboration at the Gran Sasso National Laboratories of the Italian National Institute of Nuclear Physics that conducted this investigation have thus obtained experimental evidence that the CNO (carbon-nitrogen-oxygen) cycle, which produces those neutrinos, powers the nuclear fusion that occurs in the solar core. This cycle is predominant in stars with a mass greater than the Sun, and this adds importance to the evidence offered to a theory developed more than 80 years ago.