From your link: > This result therefore paves the way towards a direct measurement of the solar metallicity using CNO neutrinos. Our findings quantify the rela

From your link: > This result therefore paves the way towards a direct measurement of the solar metallicity using CNO neutrinos. Our findings quantify the relative contribution of CNO fusion in the Sun to be of the order of 1 per cent; I find it amazing that we can analize the composition of the core of the Sun measuring the energy of the neutrinos. (Photons are not useful, because they bounce a lot of times before escaping from the Sun, so they provide only information about the outher layers.)