Moreover, though neutrinos come in different types, or flavors, they can switch from one type to another as they travel near the speed of light. The Jiangmen Underground Neutrino Observatory (JUNO) will be one of the world’s most powerful neutrino experiments, along with the Hyper-Kamiokande (Hyper-K) in Japan and the Deep Underground Neutrino Experiment (DUNE) in the U.S. Existing evidence shows that two of the flavors are close in mass and that the third one is different. Using accelerator-based neutrinos, DUNE will be able to measure the particle’s mass ordering with the greatest precision. “JUNO’s result on the neutrino mass ordering will help DUNE make the best possible discovery and measurement of CP violation,” Lykken says.